Only one year later BGBlitz and GnuBG met again in the city with the oldest university in the Netherlands. Unfortunately Nikos couldn't attend, but another opponent from the far east was announced: Elder_HA from China. Unfortunately Elder_HA was not yet ready for prime time. The UI was unstable and operating by the command line was so error prone that finishing even a single game was a challenge, not to mention a whole match, so it was only GnuBG vs. BGBlitz.

The first match to 15 points was plain sailing for GnuBG. Although BGBlitz started with 2 plain wins, it had no chance at all. GnuBG won 5 of the next 6 games and got this home easy with 15-3.

The second match was much closer. GnuBG had a better start and led 8-4 after six games, but BGBlitz won the next 4 and led 13-8. GnuBG fought back to 12-13 but BGBlitz won the next game. One match each.
One very interesting position with many attractive moves to choose from. Unfortunately only one is correct and all others are blunders... Can you spot it?

Image of position XGID=-c---BEaD-A--Bb--a-b-bbAb-:1:-1:1:62:5:8:0:15:10
Pos-ID: s5kYEDiwzxMDEA     Match-ID: QQn5AYAAKAAE

GnuBG:8 - BGBlitz:5 in a 15 point match.
BGBlitz to move 6-2

The third match started again lopsided and BGBlitz led 7-0 after 4 games. Just 3 games later GnuBG evened out to 7-7 but BGBlitz started a good finish. It ended with an classical Blitz, where GnuBG had only the opening move to decide and was slashed away.

The fourth match saw GnuBG taking the lead, and constantly extending it, winning 15-6 finally. So it was 2-2 after four matches, the final match has to bring the decision.

The fifth match had a good start for GnuBG leading 5-0 after just two games, 9-5 after eight games and 14-10 after 14 games, but BGBlitz refused to loose and finally after 16 games it was 14-14 and a very interesting game followed. It was a fight with teeth and claws. Around move 25 BGBlitz got a decent advantage started collecting blot after blot. Things started to get weird when GnuBG hit with the 3 in this position:

Image of position XGID=-B-aB-BA---aB-a-a-bcbbbBCA:0:0:1:31:14:14:0:15:10
Position-ID: bLtJBAhjFgyAXQ Match-ID: MIHsAeAAcAAE

GnuBG am Zug mit 1-3

At least I feel there is no need for further timing. The plan doesn't work well and ended with GnuBG having 9 checkers on the 24 and Bar-point and then it started to get really spooky. See here:

Image of position XGID=-B--B-------B------BA-adF-:0:0:1:51:14:14:0:15:10
Position-ID: XgAAwBhgwMIPAA Match-ID: MIH0AeAAcAAE

gnubg to move 5-1

Many moves come to mind, maybe the simply 24-18, but surely not 24-19,4-3!
In Move 53 GnuBG hit the last remaining checker and most probably due to the very unusual position, made some weird moves like:

Image of position XGID=aB-AA----A--B------C-A-AC-:0:0:1:32:14:14:0:15:10

gnubg to move 3-2

Piling another checker to the 19.

Image of position XGID=-B-A-a---B--A------D---ACA:0:0:1:53:14:14:0:15:10

GnuBG - 14 Bgblitz - 14 in a 15 point match.
GnuBG to move 5-3

Again several choices, but the 19 seems to be magnetic.

Image of position XGID=-B-A-----B--a------E--AABA:0:0:1:51:14:14:0:15:10
Position ID: ABAATGAAPmoBAA     Match ID: MIHmAeAAcAAE

GnuBG - 14 Bgblitz - 14 in a 15 point match.
GnuBG to move 5-1

What would be your choice? b-20,23-22 maybe? Then 55 is nicely blocked, but what is GnuBGs move? You might guess it already: Bar-19. Another wasted checker and also weird: XGs rollout chooses the same move!

Image of position XGID=-B-A-----B---------F-aAAB-:0:0:1:21:14:14:0:15:10
Position ID: CAAATGAAftQAAA     Match ID: MAHlAeAAcAAE

GnuBG - 14 Bgblitz - 14 in a 15 point match.
GnuBG to move 2-1

What would be your choice? 23-21,22-21 or hitting and playing the other die from the 19? Oh no, you have too few checkers on the 19 so 22-21*,21-19 is the move made.

Image of position XGID=-B-A---a-B---------G---AB-:0:0:1:31:14:14:0:15:10
Position ID: AAACTGAA/tAAAA     Match ID: MIHlAeAAcAAE

GnuBG - 14 Bgblitz - 14 in a 15 point match.
GnuBG to move 3-1

A good opportunity to spread the checkers but you surely agree that 23-19 is asked for? XGs choice 19-18,9-6 doesn't convince me either.

Image of position XGID=-B-A-----B----a----H----B-:0:0:1:54:14:14:0:15:10
Position ID: AAQATGAA/sEAAA     Match ID: MIHyAeAAcAAE

GnuBG - 14 Bgblitz - 14 in a 15 point match.
GnuBG to move 5-4

Here GnuBG even denies hitting, but piles another checker on the 19 with 24-19,9-5. XG choice 19-14,9-5 looks better but far less convincing to me as the simple 19-14,19-15.

Image of position XGID=-B-A-A---A---------I--a-A-:0:0:1:32:14:14:0:15:10
Position ID: BAAATEIA/oMAAA     Match ID: MIHpAeAAcAAE

GnuBG - 14 Bgblitz - 14 in a 15 point match.
GnuBG to move 3-2

At least GnuBG now hits, but as always continues to the 19, finally having 10 checkers collected on the 19 point. XGs rollout agrees....

XG analyzes gave GnuBG a PR of 0.34 for this game and 0.62 for BGBlitz. Sure due to the already low winning chances the errors are small, but 0.34 (or 0.13 for the whole match) implies a close to perfect game to me. Due to the move selection of XG, I feel that XG is in this very unusual positions a bit off the mark.
Anyway BGBlitz finally won the decisive match 15-14 and the title.

The matches at a glance:


The level of play was far beyond human level for both engines as expected (with the exception of the weird moves in the last game) . You can download the matches here.

The Backgammon event was an enjoyable experience, it happened in a very friendly and relaxed atmosphere, which isn't taken for granted. In "Einstein w├╝rfelt nicht" one participant was so upset about the dice, that he smashed his notebook with his fist, a bit irritating when you sit next to him....

The event it is a matter of heart for the organizers and they deserve a big "thank you" for their great work.

Here are some photographs from the Olympiad 2016 and the Naturalis in Leiden. The Naturalis is a national museum of natural history and a research center on biodiversity.
Nardy at work
Nardy at work
image of Frank and Nardy
Nardy and Frank
winning ceremony
The winning ceremony.
a rhino on the floor
Where do you meet a rhino on the floor? Naturally in the Naturalis...
close up of a dinosaur
close up of a dinosaur
pretty large dinosaur
a pretty large dinosaur
giant crab
How large a crab can be?