What conversion formula would you recommend we use for players who have no USCF rating but have a FIDE rating?
One of the three given in the USCF rulebook (USCF = FIDE + 50, USCF = .895(FIDE) + 367, or USCF = FIDE + 100) the formula given in the USCF rating system document (chesstour.com/foreignratings.htm) or something else?
An important question to ask is what is the FIDE rating of the player? Also, is the FIDE rating an established or provisional rating. The conversion formula selected may depend on the rating. Higher ratings are easier to convert; those players with 2000+ FIDE ratings are likely to be in the open section and are more likely to be current. The low ratings that FIDE gives are more difficult to assess. Is a 1600 FIDE like a 1600 USCF or more like a 1800+ USCF? The last thing you want is to have FIDE rated players sandbagging your class sections.
Conversion is a tricky thing. The material in the rulebook came from the CCA before their current formula came into use. I have seen organizers and TDs that are concerned about sandbaggers pick a conversion formula and then round that calculation up into the next 100 point floor (Example: After the adjustment a player has a 1780 rating–round it up to an assigned rating of 1800.). Some TDs don’t bother to adjust the rating but instead assign a US Chess rating = to the floor of the next highest prize group (Example: A FIDE rating of 1750 gets adjusted to a US Chess rating of 2000 in a tournament where the prizes–or sections–are Open, U2000, U1600, etc.). I suspect that most FIDE rated players are not sandbaggers, but those who are have made life difficult for the rest of us. If you are not worried about sandbagging, then just pick an adjustment method and go with the results.
One should probably bear in mind that lower FIDE ratings are less likely to be accurate than higher FIDE ratings. Just within recent memory (the last eight years), the lower limit on FIDE ratings has been lowered from 1800 to 1600 to 1200 to 1000 (the current limit). As a result, there aren’t many FIDE ratings below 1800, and those players with lower ratings are likely to have gotten those ratings by losing most of their games to higher rated players. I would be reluctant to trust any conversion formula for such ratings.
I’ll bite: what’s a FIDE provisional rating?
Alex Relyea, FA
This topic is a spin-off from Allocation of prize fund.
When I played in a tournament in Virginia, I noticed that a few of the juniors had FIDE ratings that were under 2000. They were based on a few games that they played in both junior and regular events. There are many events in the MD/DC/VA metro area that are FIDE rated allowing juniors to get FIDE ratings. Sometimes those FIDE ratings are above their USCF rating. Many adults have FIDE ratings that are lower than their USCF ratings.
To clarify: FIDE does not have the concept of a “provisional” rating. One must have at least five games against rated opponents, scoring at least one-half point. (The games do not have to be in one event.) A player with fewer than five games does not have a provisional rating, or any rating at all.
There’s also a peculiar asymmetry in the FIDE rating system. When an unrated player plays a game against a rated player, the game counts for rating for the unrated player but not for the rated player. (Full disclosure: round robins are handled differently by the FIDE rating system.)
Possibly interesting data about the distribution of FIDE standard ratings from the December FIDE rating list:
2800- 3
2700-2799 42
2600-1699 210
2500-2599 677
2400-2499 2,163
2300-2399 5,563
2200-2299 12,317
2100-2199 20,329
2000-2099 27,362
1900-1999 27,417
1800-1899 27,509
1700-1799 25,305
1600-1699 21,506
1500-1599 17,426
1400-1499 13,362
1300-1399 10,384
1200-1299 7,679
1100-1199 5,373
1000-1099 3,347The distribution for US Chess regular ratings from the January, 2016 golden database:
2900- 1
2800-2899 15
2700-2799 60
2600-2699 207
2500-2599 426
2400-2499 610
2300-2399 1,012
2200-2299 2,105
2100-2199 2,910
2000-2099 4,905
1900-1999 6,654
1800-1899 9,545
1700-1799 11,988
1600-1699 15,574
1500-1599 18,347
1400-1499 21,949
1300-1399 24,910
1200-1299 29,604
1100-1199 32,661
1000-1099 36,149
900-999 38,913
800-899 42,915
700-799 44,921
600-699 45,332
500-599 44,550
400-499 42,104
300-399 38,208
200-299 33,260
100-199 60,268
0- 99 78Let’s compare US Chess regular and FIDE standard ratings for players who have both. This table shows the distribution of (US Chess regular rating - FIDE standard rating). A positive value means the US Chess rating is higher; a negative value indicates the FIDE rating is higher.
800 - 899 1
700 - 799 0
600 - 699 2
500 - 599 6
400 - 499 10
300 - 399 79
200 - 299 362
100 - 199 1448
0 - 99 4095
-199 - -100 403
-299 - -200 139
-399 - -300 50
-499 - -400 24
-599 - -500 11
-699 - -600 7
-799 - -700 3
-899 - -800 6
-999 - -900 3
< -1000 3I have to wonder whether any of the outliers are cases of “mistaken identity” (a FIDE ID incorrectly assigned to the wrong US Chess member). The player whose US Chess rating exceeds his FIDE rating by more than 800 points has a regular rating of 2043 from recent activity (December, 2015) but a FIDE standard rating of 1242.
Be aware that many of the players with unusually low FIDE ratings are young children who earned their initial FIDE ratings at the World Youth, especially in U8 or U10. Those ratings are based on the opponents, who are themselves underrated kids. However, those initial FIDE ratings will remain unchanged until the players are strong enough to play in Open sections at domestic tournaments.
Michael Aigner
At the last tournament I directed, we had one foreign player with a FIDE rating and no USCF rating. I forgot to do a conversion at all (this was a first-time situation for me), and just used his FIDE rating for pairing purposes and prize eligibility. Fortunately, this made no difference, as he was the highest-rated player in the tournament either way. USCF automatically did a conversion in the rating report. I don’t know what formula they used, but the result was FIDE 2158 = USCF 2221.
No matter what rating you submit in the tournament report, USCF will look up the correct (and most recent) rating and use it in all calculations.
This also includes any FIDE conversions.
Bill Smythe
The conversion from a FIDE rating to a US Chess initial rating is documented in the rating system specification.
I used that to estimate initial US Chess ratings for the two European players I had in my WGM tournament. Both were fairly close, but wrong.
Alex Relyea
As noted, USCF used the formula listed in the rating system info document for FIDE ratings over 2000: 20 + 1.02 x FIDE rating
Interesting. The Rulebook lists three conversion formulas, but not the one listed in the rating system doc. Maybe that should be added.
Also, if you count the CCA policy, there are no fewer than five different initial ratings to assign a player with a FIDE rating but no USCF. They are fairly close, but not ‘that’ close. For your player, the following initialized ratings are possible:
2200 (CCA policy)
2208
2221 (Ratings doc formula)
2258
2298
Hmm. I never had to do this conversion in the local/club events I directed in the wilderness, but we did have a BCF conversion once. Fun stuff.
I think Mr. Mark misunderstands. There is only one initialized rating, while the other four are to be used for pairing and prize purposes only TO BE FAIR TO THE OTHER PLAYERS. No one ever knows what rating will be used for calculating their post-event rating.
Alex Relyea
The conversion formulas used to determine an initial US Chess rating from a FIDE rating changed after publication of the fifth edition. (It may have been about five years ago, as memory serves.)
I’m not sure I would add the conversion formulas from the rating system specification to the Official Rules of Chess. This is for several reasons:
- The conversion formula is a bit complicated. (It’s not rocket science, but it’s more than a simple one-liner.)
- The purpose of that section of rule 28 is to provide an estimate for pairing and prize purposes (and for section eligibility). A TD should never tell a player that the estimate used will be the player’s initial rating. For pairing and prize purposes, the approximation is good enough. (I am counting the seconds until a certain regular forum participant says “no it isn’t.”)
- The conversion formula to determine the initial US Chess rating can (and does) change from time to time. The rating committee is responsible for tracking the relationship between FIDE and US Chess ratings and adjusting the rating system specification accordingly. Changing the details of the rating system only requires Executive Board action. Amending the Official Rules of Chess requires a two-thirds vote of the Delegates.
Having written all that, I would certainly not fault a director who chose to use the formula from the rating system specification to assign a rating for pairing and prize purposes, and I think such a decision is easily justified. Indeed, I have done this myself. But I would also not fault a director for using the simpler conversion formula specified in rule 28.