I spent some time on this. The best racing formula is K-Star (short for Keith*). There are several videos discussing the topic in general
https://www.youtube.com/watch?v=9qeStT6VtVg -Joseph On Thu, 13 Feb 2025 at 09:20, Wayne Joseph <[email protected]> wrote: > Hi all, > > I saw some squiffy behaviour in the Race Formulas - Keith Count feature, > which did not agree with XG's conclusion. > > Please see short video here: > https://fy0o.short.gy/wj_cy_keith_count_bug_gnubg > > XGID=-ABBA-C------------e--aaa-:1:1:1:00:0:0:0:3:10 > > GNUbg > > FR8AANpyAAAAAA:UQlgAAAAAAAE > > Chris Yep kindly cross-verified my suspicion as a bug. > > An excerpt of Chris' verification is below. The full thread on Facebook > can be found here: > https://www.facebook.com/groups/backgammonstrategy/permalink/3817038441898133/ > > Not critical, but please can the bug be fixed? > > Thank you. > > -------- > > >> CY > *Yes, this error (bug) has likely existed for many years.I just checked > all the boundary cases now. XG's doubling advice matches that given in Tom > Keith's paper if the difference ("leader's" Keith Count minus "trailer's" > Keith Count) is 2, 3, or 4. GNU's doubling advice matches that given in the > paper if the difference is 3 or 4; however, if the difference is 2, GNU > gives incorrect doubling advice (as you observed in your bearoff > position).In addition to this error, however, GNU also doesn't truncate the > "1/7" adjustment. According to the paper, the player on roll is supposed to > increase his count by one seventh of the previous count, rounding down. GNU > doesn't do any rounding. For example, if GNU's count is 36, it will > increase this count by 36/7 (5.14) for a final count of 41.14. XG, on the > other hand, will round the final count down to 41, as specified by the > paper. Because GNU doesn't truncate this adjustment, additional errors > occur (example below).In the position below, XG evaluates the Keith Counts > as 41 to 37, so it recommends double/take. GNU, on the other hand, > evaluates the Keith Counts as 41.14 to 37 (a difference of 4.14, which is > more than 4), so it recommends a no double. In this position, XG is correct > and GNU is incorrect (according to the paper).* > [image: May be an image of text that says "19 20 21 22 23 24 13 1314 14 15 > 16 131415161718 1718 17 18 WNW 64 KG MAI Ganmon eXtreme ko extreme Ganmon > 121110 121110987 8 12 11 10 9 654321 3 6 5 4"] > <https://www.facebook.com/photo.php?fbid=10231708555754825&set=p.10231708555754825&type=3&__cft__[0]=AZWP4gT20yOUew61xt8Vj7zf0P-Cbjd9CCfNbyy7VFEWOE-6qQ5wPtr21YFqKUtQUOYGhET785qp1dmj4MxJLXbT1wyhqYHAehqHe9QgUvqBVlZ0PhQkgzhGksZNq6DPuE7PUBvP8SFxholSKkJ5-uTW8buKTe7C7mTzbG7I5Pa2a1WOf0hpX9jUZ3X8TnYSWm5E6VxM6y8a_vXXwoNNBJc-&__tn__=R]-R> > >
