Over a year ago the International Axe Throwing Federation (IATF) launched the Collins Rating System. This system is based on the Elo rating system widely used in chess, online gaming and other kinds of head-to-head competition. The system considers the level of stakes at hand as well as the value of one-on-one competition, and has been adapted by the IATF to accommodate the complexities of axe throwing. The Elo system was selected because it ranks players in head-to-head competition through a mathematical equation. 

This system works well for the IATF. We value head-to-head competition, both in our sport and as sports fans, and see the value in a rating system that rates players according to skill and skill improvement. We operate in the spirit of fairness in competition; all venues operate differently, but still have an accurate system of rating for throwers across all IATF organizations. 

Key Principles

  • Head-to-head competition should be used to assess skills and determine ratings. (true since version 1.0)
  • Beating lower rated players is less valuable than beating higher rated players. (true since version 1.0)
  • Higher levels of competition should raise the stakes by allowing larger adjustments, if required to better reflect players’ relative skill. ie. IATC has higher stakes than Regionals which in turn has higher stakes than league playoffs. (true since version 1.0)
  • Throwing an 81 and winning the tiebreaker should never result in a downward adjustment (this became clear from version 1.0)
  • Throwing more frequently should not disproportionately inflate ratings (true since version 1.0, however version 1.1 created a deviation from this principle, version 1.2 addresses the inflation from version 1.1)

Reviewing How it Works: 

Each players’ rating goes up or down at the end of a match based on the result of each round. Players have their rating compared to the rating of their opponent. If the higher rated player wins, as expected, adjustments are generally small. However, if the lower rated player wins, an adjustment in ratings moves both players’ ratings – up for the lower rated player, and down for the higher rated player.

CRS 1.0 – The first version of CRS adjusted players rating based on winning or losing rounds within a match. These adjustments were affected by the ratings of their opponents as well as the expected result going into the match. 

For example, in version 1.0 (example A): Alice and Bob are throwing a match. Alice is a higher rated player than Bob. When Alice wins the match, her rating goes up slightly and Bob’s goes down slightly, by the same amount. However, if Bob (as the lower rated player) were to win the match, his rating would go up and Alice’s rating would go down, again by the same amount.

Another example (example B): A highly rated player who ties a lower rated player at 81 and wins the tiebreaker. Based on their rating before the match, the lower rated player has exceeded their expectation by taking the match to a tie breaker, and needed an upward adjustment. Since in CRS 1.0 the adjustments were always equal, but opposite, the higher rated player’s rating would be adjusted downward to match the lower rated player’s increase after the match. The result of which was that the two players were now more closely rated, which was the desired result of the system.

Transition to Version 1.1 – After listening to feedback from the community and observing how the System worked in a live setting, it was clear that the rating calculation was not performing as desired in some match scenarios. It was determined that the cause was that ties at 27 were being treated in the same manner as other ties, which, since this is the maximum score, felt like a penalty for the higher rated player, as outlined in example B, described in the previous paragraph. The natural question was “How could I have done better? Why would my rating go down in that scenario?”

Version 1.1 – To address how ties at 27 were impacting rating adjustments, a modification to the calculation was made to treat these rounds as a win in that round for both players instead of a tie in that round for both players; the rationale being neither player could have done better, so this should count as a win. This meant that in matches with ties at 27, it was now possible for both players to be adjusted positively since both players threw as well as possible in that round. This effectively created new “bonus” rating points, adding them to the system. It also meant that the lower rated players’ adjustments were greater than the higher rated players’.

This modification created a new issue wherein players who were tying at 27 more frequently, especially by throwing in multiple leagues, were receiving a disproportionate boost to their ratings since these “bonus” rating points threw off the original balance of the system. This effect was more pronounced for the lower rated players.

For example, in version 1.1 (example C): Alice and Bob are both rated 1600. Alice and Bob both throw 27s at the same percentage rate, however, Alice throws in one league and Bob throws in four leagues. Bob stands to gain four times the “bonus” rating points.

Following the release of Version 1.1, after listening to community feedback and observing actual match rating adjustments, it was clear that another modification would be needed to align the CRS to some key principles.

Version 1.2

A modification to the calculation was made that would treat ties at 27 as follows:

  • The higher rated player’s round is treated as their expected result in the round. This means that it is no longer possible to tie at 81 and win the tiebreaker and have the rating adjusted downward.
  • The lower rated player’s round is treated as a tie in the round (as with Version 1.0). It should be noted that a tie for the lower rated player is better than expectation. This means that throwing an 81 against a better player can result in a positive adjustment, even if the tie breaker is lost. However, it also avoids the inflated rating adjustments of Version 1.1.

For example, in version 1.2 (example D): Alice and Bob play a match. Alice is rated 1700 and Bob is rated 1500. Alice is expected to win. They both throw three rounds of 27 and tie overall at 81. Alice wins the tiebreaker.

The resulting rating adjustment for each of the CRS versions would be (see The Full Nerd Version below):

CRS VersionAliceBob
1.0-3+3
1.1+5+10
1.2+1+3

This particular case highlights the differences between the versions. CRS 1.2 produces adjustments that best align with the key principles behind the CRS.

Players should note that when version 1.2 is implemented there will be a shift in rankings. Multiple tests have been carried out to assess the accuracy of version 1.2 and our team has concluded that this latest version is the most balanced and fair while maintaining the key principles of head-to-head competition that we hold dear in our sport.

Version 1.2 will be launched on Friday July 17, 2020. For those interested in a more detailed understanding of the rating calculation please see The Full Nerd Version below.

Remote Matches

We are excited to launch the IATF AxeScores app soon, which will include a remote challenge feature. The app will increase players ability to seek out higher levels of competition across all IATF players. Players who would normally not be able to geographically play against each other on a regular basis will now be able to throw heard-to-head matches via the app. These matches will count towards CRS ratings at half of the value of regular league play. This reflects the principles of competition outlined above wherein we value higher profile matches and tournament at higher rating multipliers ie. Playoffs have higher stakes than regular league play which in turn has higher stakes than remote matches. This also reflects the level of supervision during those matches. Remote matches will be regulated using tools within the app. Because there is less oversight and officiating, the matches’ rating value will be less.

The Full Nerd Version – CRS 1.2

The procedure for calculating rating adjustments is as follows:

Let the initial rating of a player be pi and the initial rating of the player’s opponent be qi.

Let the player’s match expectation value be E. The expectation value is calculated as:

E= 2 / 1+10qi – pi / 400

It follows that  pi >qi1 < E < 2  and pi<qi0 < E < 1.

Each round in the match is evaluated to determine the result. A win is valued at 1, a loss at 0 and a tie at 0.5. In the case of a tie at 27, if pi>qi the round is valued at half the expectation value (E/2).

The set of the player’s round results is g1,g2,…,gnwhere g1 is the player’s result in round 1 and gn is the player’s result in round n and n is the number of rounds.

Let the player’s match result value be R. The match result value is calculated as follows:

R=2nk = 1ngk, where n is the number of rounds.

Observe ∵ 0<gk<10<R<2.

Let the player’s rating adjustment be A. The adjustment is calculated as follows:

A=f*R-E, where denotes rounding to the nearest integer, and f*is a swing factor1.

Let the player’s final rating be pf. The final rating is calculated as follows2:

pf=pi+A

An example, for illustration:

Alice has a rating of 1700.

Bob has a rating of 1500.

Alice is the higher rated player, they are expected to win.

Alice’s expectation value is 2 / 1+101500 – 1700 / 4001.52.

Bob’s expectation value is 2 / 1+101700 – 1500 / 4000.48.

Alice’s expectation value is higher than Bob’s, since Alice is expected to win.

In round 1 Alice and Bob tie at 25.

In round 2 Alice wins 25-20.

In round 3 Alice wins 27-21.

Alice has won the match.

Alice’s round results are: 0.5,1,1.

Bob’s round results are: 0.5,0,0.

Alice’s match result is: 232.51.67.

Bob’s match result is: 230.50.34.

Alice’s adjustment is: 101.67-1.52 +1 (here 10 is the swing factor).

Bob’s adjustment is: 100.34-0.48 -1.

Alice’s rating after the match is 1701.

Bob’s rating after the match is 1499.

Since Alice won the match, and approximately by the expected amount, the adjustment is small.

Had the first round been a tie at 27 instead of 25, the results would follow:

Alice’s round results are: 0.76,1,1.

Bob’s round results are: 0.5,0,0.

Alice’s match result is: 232.761.84.

Bob’s match result is: 230.50.34.

Alice’s adjustment is: 101.84-1.52 +3.

Bob’s adjustment is: 100.34-0.48 -1.

Alice’s rating after the match is 1703.

Bob’s rating after the match is 1499.

Alice’s performance is a little better and the adjustment is a little greater. The tie doesn’t affect Bob differently though, a tie in this case is still better than their expectation.

Had Bob won rounds 2 & 3 (leaving the tie at 27), the results would follow:

Alice’s round results are: 0.76,0,0.

Bob’s round results are: 0.5,1,1.

Alice’s match result is: 230.760.51.

Bob’s match result is: 232.51.67.

Alice’s adjustment is: 100.51-1.52 -10.

Bob’s adjustment is: 101.67-0.48 +12.

Alice’s rating after the match is 1690.

Bob’s rating after the match is 1512.

Bob performed much better than expected and Alice performed worse. Their rating adjustments reflect the upset.

It should be noted that the first 28 matches a player completes in their career have an additional consideration, specifically, opponents’ ratings in these 28 matches are not adjusted unless the match is also one of the opponents’ first 28 matches. This prevents the uncertainty of new players’ ratings from affecting their opponents’ ratings in their first career season.

1 The swing factor f*is a parameter chosen to reflect the stakes of the type of match. The swing factor acts as a bounding factor on how large a rating adjustment can be for any given match of that type. Observe A<2f*. The swing factor generally increases with the level of competition or tournament profile. Regular league play has a swing factor of 10, larger tournaments can have swing factors of up to 20.

2 The calculation can be expressed in terms of source input values as:

pf=pi+2f*1nk = 1ngk-1+10qi – pi / 400-1

Definitions

where

pf is the player’s final rating,

pi is the player’s initial rating,

qi is the opponent’s initial rating,

f*is a swing factor,

gk is the player’s result in round k,

n is the number of rounds,and denotes rounding to the nearest integer.

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1. All participating member organizations will send to Round 2 a number of competitors equal to their percentage of the total IATF league enrollment during the calendar year.

2. The league enrollment is calculated as players in each season. 

1. An individual player participating in one season would count as 1, the same player participating in four seasons would count as 4.

3. Only the league members of organizations participating in Round 2 will count towards the member representation in the tournament.

1. For instance, if there are 6000 active league members across all organizations in the IATF, and they all participated in all 5 season through the year, then there would be 30,000 league enrollments in the pool of IATF representation:

1. If organization “Z” represents 10,000 of those league enrollments, and chooses not to participate for any reason, then those 10,000 league enrollments would be removed from the equation;

2. If all other organizations participate, then there are 20,000 league enrollments remaining in the equation;

3. e.g. If organization “A” represents 2,000 league enrollments, then organization “A” would represent 10% of all participating IATF leagues in Round 2;

2. That means organization “A” throwers will represent 10% of those competitor ‘seats’ in Round 2 of the tournament

1. eg. 25 seats would be organization A throwers if the final round hosts 250 total competitors, 10 seats would be organization A throwers if the final round hosts 100 total competitors

2. In the case of a decimal point percentage, the IATF will round up or down accordingly to match the amount of throwers in the final stage.

3. When applying these calculations to any official tournament numbers, keep in mind that 1 spot in Round 2 is always reserved for the winner of the previous year’s tournament, so be sure to remove that seat from the equation.

**Please note that due to the COVID-19 crisis, representation for the 2021 IATC will be determined by a median number between the organization’s seats from the 2020 IATC and their representational seats from the 2020 season based on the above equation.

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1. Format and Seeding

1. Round 2 of the tournament is a double elimination tournament bracket. The rules and format of Round 2 matches continue using the Premier ruleset and scoring system also used to score Round 1.

2. These competitors are the top throwers from each organization as determined by Round 1.

3. The seeding within this round of the tournament is determined by the player’s performance in Round 1.

2. Round 1 of the IATC tournament will be held at all IATF organizations on one set day each year***:

2. Previous Year’s Champion

1. The winner of the previous year’s IATC tournament is guaranteed entry into Round 2 of the tournament, however, will still need to throw in Round 1 for seeding purposes.

3. Attendance

1. If a competitor is late for their first match and misses it, then they automatically forfeit that match and move to the “B” Bracket and their opponent will automatically advance to the next set of matches:

2. If the same competitor who missed their first match also misses their second match in the “B” bracket, they automatically forfeit that match and are eliminated from the tournament.

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1. Round 1 of the IATC tournament will be held at all IATF organizations on one set day each year***:

1. All scoring for Round 1 will be based on the Premier ruleset and scoring system.

1. See Premier ruleset in section (1.4.1)

2. All qualifying throwers from every league will throw for Round 1 on the set date, at their home venue.***

2. Round 1 of the IATC tournament will be held at all IATF organizations on one set day each year***:

Format

1. In Round 1 of the IATC, players will be randomly split into groups of four. Players will take to their assigned lane, then throw the equivalent of 5 matches (a total of 75 throws) and 15 Big Axes:

1. In this round, competitors are not facing off one on one against an opponent, as in standard competition, rather, the goal here is to throw for the highest point total possible;

2. Once each group of 4 competitors has taken to their assigned lane, they will throw 15 axes in a row, scoring points under IATF Premier scoring rules with the option to call and throw for Clutch every 5th throw;

3. Every 15 axes, scores will be tallied and competitors will move one lane to the right and throw another 15 axes until everyone has thrown 75 times:

1. Competitors on the farthest right lane will move to the far left lane of the arena to score their next throws when necessary;

2. Between every set of 15 throws, competitors can request a board change similar to regulation competition.

3. Every 15 axes, scores will be tallied and competitors will move one lane to the right and throw another 15 axes until everyone has thrown 75 times:

1. Competitors on the farthest right lane will move to the far left lane of the arena to score their next throws when necessary;

2. Between every set of 15 throws, competitors can request a board change similar to regulation competition.

4. Each set of 15 throws will count as the score for 1 match totaling 5 match scores for every competitor. Players will receive the average match score from these 5 matches:

1. e.g. for a competitor’s first set of 15 throws they throw a total match score of 42, in their second set, a 67, in their third set, a 61, in their fourth set 60, and their fifth set another 60. The total scored points obtained over the 5 matches is 290, divided by 5 to obtain an average score of 58.

5. Upon completion of these 75 throws each competitor will throw 15 consecutive big axes.

1. A competitor may call Clutch at any point during their 15 big axe throws.

2. Competitors are not required to score a bullseye prior to being able to call Clutch in these 15 throws

3. Their combined score from these 15 throws will be used as a tiebreaker in the case that throwers have the same Round 1 average as another thrower. 

6. Upon completion of this round, competitors will be ranked against others from the same organization based on their Round 1 average and using Big Axe tie breaker score if needed:

1. The Round 1 rank will be used to determine who represents each organization based on the percentage of representation calculation for Round 2 of the tournament (See section 7.1 below)

2. The Round 1 score will also be used to seed a competitor that moves onto Round 2 of the IATC.

***exceptions may be made due to COVID-19

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To qualify for the International Axe Throwing Championships players must qualify via six possible routes for IATC Round 1 to advance to the Final Round.

1.Being the previous year’s IATC Champion

2.Winning a Regional Tournament

3. Earning a spot in the top 8 Champion Points of a Premier Rules axe throwing league (The Top 8 Rule)

4. Having an average of 70 or better in three non-concurrent axe throwing league seasons (The 70 Rule)

5. Earning a spot in the top 4 Champion Points of a Standard Rules axe throwing league (The Top 4 Rule)

6. Winning a Wild Card Tournament

1. Regional Tournaments

Regional tournaments are a double elimination tournament within a single regional division where the winner will automatically qualify for Round 1 of the IATC.

2. Top 8 Rule

1. Champions Points are awarded at the end of every regulation axe throwing league season and totaled at the end of the calendar year. The top 8 Champions points earners in each Premier Rules league qualify for Round 1 of the IATC.

2. These top players, ranked by Champion Points earned in a league, qualify to represent that league. Players that have already qualified by winning a Regional tournament are removed from consideration, meaning a league’s top 8 may adjust, with the fifth player moving into the top 8 if a regional winner is removed.

**Home league consideration and Champions Points moves were elements we applied prior to the COVID affected 2020-2021 season. These considerations are currently not factors for this qualification period due to all individual seasons allowing their top Champions Points leaders qualification into Round 1.

3. The 70 Rule

1. This route to IATC contention is intended to ensure that skilled players in competitive leagues are given an opportunity to qualify. To qualify under the 70 Rule, an axe thrower must not have already qualified via a Regional Tournament. To qualify, a player must throw an average of 70 or better in three seasons during the IATC qualifying year. The three seasons do not have to be back-to-back, nor do they have to be in the same league night or ruleset (please note; only Standard and Premier rulesets are considered); but they have to occur within one organization and they must be in three separate time frames over the course of that calendar year.

4. Top 4 Rule

1. Champions Points are awarded at the end of every regulation axe throwing league season and totaled at the end of the calendar year. The top 4 Champions Points earners in each Standard league qualify for Round 1 of the IATC.

2. These top players, ranked by Champion Points earned in a league, qualify to represent that league. Players that have already qualified by winning a Regional tournament are removed from consideration, meaning a league’s top 4 may adjust, with the fifth player moving into the top 4 if a regional winner is removed.

**Home league consideration and Champions Points moves were elements we applied prior to the COVID affected 2020-2021 season. These considerations are currently not factors for this qualification period due to all individual seasons allowing their top Champions Points leaders qualification into Round 1.

5. Wildcard Tournament

1. The winners of the Wildcard Tournament qualify for IATC Round 1. Only players that haven’t yet qualified (by the previous means outlined above) are eligible to compete. *See Wild Card Tournament.

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Champions Points are awarded to players at the end of every Standard and Premier league season only, as summarized below, based on where they place at the end of regulation (Week 7) play:

1st place receives 16 points;

2nd place receives 15 points;

3rd place receives 14 points;

4th place receives 13 points;

5th place receives 12 points;

6th place receives 11 points;

7th place receives 10 points;

8th place receives 9 points;

9th place receives 8 points;

10th place receives 7 points;

11th place receives 6 points;

12th place receives 5 points;

13th place receives 4 points;

14th place receives 3 points;

15th place receives 2 points;

16th place receives 1 point.

2. Players are also awarded Champions Points based on how they finish in their playoff bracket at the end of each league season:

1st place receives 8 points;

2nd place receives 4 points;

3rd place receives 2 points;

4th place receives 1 point.

Tie Breaker

1. If two players are tied for Champions Points, then Total Score for the season is used to determine the higher seed.

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Big Axe (Felling Axe): 

See Image 2.2 Below

1. A Big Axe (Felling Axe) has the following requirements

1. The axe must be a single bit blade, ie: no blade or sharpened spike may be protruding from the back of the axe head.

2. The axe must weigh between 2.75 and 3.75 pounds of total weight (handle included).

3. The handle must be wood, handle length must be at least 25″ including the handle in the eye of the blade.

4. The face (blade) of the axe must be no longer than 4 5/8″ and no shorter than 3.5” and must be fixed to the handle of the axe with an eye or pin (ie: no ‘floating’ axe heads where the head itself is wedged on a tapering handle and only held there through gravity.)

5. The axe head must have a minimum height of 2” as measured parallel to the handle.

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1. Standard Throwing Axe (Hatchet) Requirements: see image 2.1 below

1. The handle must be made from wood;

2. The axe must be a single bit blade, ie: no blade or sharpened spike may be protruding from the back of the axe head.

3. Handle Length:

1. The length must be a minimum of 13” long and cannot exceed a maximum of 17” long:

1. This measurement begins from the bottom (butt) of the handle to the top of the axe head. See Image 2.1 (2.1.2);

2. If any of the handle protrudes from the top of the axe head (eye) it does not count towards the minimum or maximum handle length. See Image 2.1 (2.1.1).

4. Weight:

1. The axe must weigh between 1.5 and 2.5 pounds of total weight (handle included).

4. Blade Length:

1. The face (blade) of the axe must be no longer than 4″ and no shorter than 3” and must be fixed to the handle of the axe with an eye-wedge or a pin (ie: no ‘floating’ axe heads where the head itself is wedged on a tapering handle and only held there through gravity.)

2. The axe head must have a minimum height of 1.5” as measured parallel to the handle.

3. The axe head may have a maximum length (from face to butt) of 7”

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IATF arenas have 4 throwing lines:

1. The solid Red Fault line

2. The solid Black standard throwing line

3. The dotted, thin Blue Big axe throwing line

4. The solid Yellow perimeter line

These lines must be painted on the grounds of all IATF members venues to ensure throwing distances and safety regulations are properly followed.

1. The Red Line

1. The red foot fault line serves as a safety mechanism to ensure players remain a minimum distance from target while throwing

1. The player must remain behind this line until both throwers have completed their throw.

2. The front of the red line is measured at 110” from the subframe of the target, as if the face boards reached all the way to the ground:

1. The fault line must be a minimum of 6” thick to be clearly visible to throwers and painted across the entire length of a throwing arena.

2. The Black Line

1. The black line is where players will throw their standard throwing axe from:

1. When a thrower prepares for their throw, their back foot must begin completely behind the black line.

1. The front of the black line is measured at 170” from the subframe of the target, as if the face boards reached all the way to the ground:

1. It must be painted 10” thick and is 52” in length from left to right;

2. The black line must be centred with the centre of the bullseye:

1. This means that measured from the centre of the black line there should be 26” on the left and 26” on the right to be split evenly from the centre of the bullseye.

3. This line also doubles as the big axe foot fault line.

3. The Blue Line

1. The blue line is the starting point for players to throw Big Axe:

1. When a thrower prepares for their throw, their back foot must begin completely behind the blue line.

1. The front of the blue line is measured at 220” from the subframe of the target, as if the face boards reached all the way to the ground:

1. It must be painted 2” thick and is 52” in length from the left to right:

1. This means that measured from the centre of the black line there should be 26” on the left and 26” on the right if it is split evenly from the centre of the bullseye.

2. The line should be dotted to illustrate it is not always in use.

4. The Yellow Line (Perimeter Line)

1. The Yellow line is the visual separation of throwers and spectators;

1. The distance of the yellow line may vary by a few inches venue to venue, as it is not related to the mechanics of throwing an axe, but is an important representation of where the throwing arena begins;

2. If you are not in the lanes competing, you are not to cross the yellow line.

The following diagram represents a bird’s eye view of a single axe throwing lane, with all the lines painted on the ground. All measurements are taken from the back of the plywood backboard as if it reached all the way to the ground.

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1. Target Rings

1. The centre of the bullseye sits in the centre of the middle 2×10 [note that a 2×10 is actually 9 1/2 inches wide thereby making the centre 4 5/8″]:

1. Bullseye is 7″ in diameter;

2. Red (3 point ring) is 17″ inches in diameter;

3. Blue (1 point ring) is 27″ inches in diameter . See image 3.2-A below

2. The centre of the bullseye measures 63″ from the floor;

3. Left or right side boards may be mounted at varying heights on the backboard to keep knots away from point areas:

1. Sideboards are always mounted blank so their height position doesn’t affect the location of the Clutch or point areas.

Image 3.2-A

2. Clutches™*

1. The diameter of the Clutch is 2 inches;

2. The innermost edge of the Clutch sits 4 ¼ inches from the seam between the side and centre 2×10:

1. The centre of the Clutch is 5 ¼ inches in from the seam, and 40 ½ inches from base of target face board. That means the base of the Clutch 39 ½ from the base of the target face board. See image 3.2-B below

*Clutch: the term ‘Clutch’ is a registered trademark of BATL Global Corporation, used under license to the International Axe Throwing Federation and its members.

Image 3.2-B

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