This page is for improvements to the initial proofs.

Also, the corrections from fixing the double en passant bug are included.

It is not easy to say exactly what the criteria for improvements are.
In general, reducing the size is good, but also reducing the MAXREV
(maximum reversible move sequence) or maximum depth can be important too.

easy12.rev.bz2 993510 + 13191 nodes (1.1MB) f19e562db9e077b926c3998cbeae5e3f (2016 Oct 25)
e3c6.rev2.bz2 2013313 + 32724 nodes (2.2MB) 40e0976ed0e76ad8196ca9b201c0cda9 (2019 Apr 15)
e3Nc6.rev2.bz2 9107578 + 269736 nodes (10MB) 562e77c035d12318e6422278229dee90 (2019 Apr 15)
e3Nh6.rev2.bz2 15256430 + 433321 nodes (17MB) bf0c2562b2a7ddd3d6edcbb543d45a63 (2019 Apr 15)

Jul 2018: Vladica Andrejic has simplified some aspects of 1. e3 g5 that are
now included. Principally, 1. e3 g5 2. Ba6 Na6 3. Qh5 Bg7 4. Qh7 Bb2 5. Bb2!
is now under 19 million nodes, compared to around 30 million for Qxh8.
e3g5.rev3.bz2 23192197 + 1916326 nodes (38MB) e1e4fae6bbe09d09de2883a5e3a3d026 (2019 Apr 15)

Re-solving 1. e3 e6 is a nightmare. Over a week now of wandering through
6-unit tablebases, and no sign of nearness to completion. I don't like the
final result in some of the endgames, but improving it looks onerous.
e3e6.rev2.bz2 38694358 + 3152521 nodes (56MB) cec66f5f8c72bcdcd6db3674da3cb468 (2017 Feb 7)

With b5, I spent a long time on 10. Nge2 for Ba6/Qb8, but ultimately this went nowhere.
e3b5.rev2.bz2 69187717 + 2964725 nodes (85MB) bbf1215f5b459ee68c7d1600127726b6 (2019 Apr 15)
e3c5.rev2.bz2  194005345 + 9529468 nodes (253MB) 150f2331f5839d9db28f74e79f352c85 (2019 Apr 15)
e3b6.no2e6.rev2.bz2 113985726 + 7152364 nodes (153MB) f482884d52f3786f13c258c9a1e35b9d (2019 Apr 15)
e3b6.2a4e6.rev2.bz2 257027998 + 27905361 nodes (453MB) 04cd282c1389c3e339c535739fe330bd (2019 Apr 15)

e3wins.rev3.bz2 718910631 + 55127558 nodes (1.05GB) 0ee75b143e0fa46500cffc8af9503736 (2019 Apr 15)

VERIFY WIN-TREE FAULT LOOPS
Loading win-tree PROOFS/e3wins.rev3
Tree size is 774038189 [5905mb]
With TBs
================================================
tb4 20146030 tb5 67873025 tb6 76281920
nomoves 29845283 = nopieces 15035073 + patt 14810210
trans 55127558 terminal 49991313 internal 668919318 forced 335209826
MAXREV 45 maxdp 261 (wtm 325233028 btm 298612292/343686290 internal)
OK