Elephantiasis: reality or myth?

[Lyudmil Tsvetkov]

You might want to test this one - I am taking the bishop side here, although this position might have its specificities.

[d]nnnnknnn/pppppppp/8/8/8/8/PPPPPPPP/BBBBKBBB w - - 0 1

Ok, I ran a 60 game tournament with 7B vs 7N out of interest. I created an set of opening positions based on the initial position you start (e.g. 1. b4 f6, 1. e4 e5, etc.). I expected the knights to win, but the results were:

Bishops won: 40/60
Draw: 15/60
Knights won: 5/60

Engine Score St Pr To Te S-B
1: Stockfish_13102819_x64_modern_sse42 21.0/30 ·········· 010101=1=1 =11011111= 01=11=0111 271.50
2: Protector_Win32 14.5/30 101010=0=0 ·········· 010==101== 101=1010== 212.25
3: Toga280513_Intel 13.0/30 =00100000= 101==010== ·········· =1010=0111 183.50
4: Texel32 11.5/30 10=00=1000 010=0101== =0101=1000 ·········· 180.25

Note that:
- all the engines evaluated the start position as good for White (up to +2)
- the bishops always had White as I forgot to have some positions the other way around

However, despite all this I think it is clear that the bishops are probably winning. Things I found:

- most engines thought 3 same-colour Bishops could win against a lone king, not realizing the importance of keeping opposite coloured bishops.
- Texel only evaluates 2B vs N as +0.50, even when the Bishops were not same-coloured. Seems a bit low as in FIDE chess 2B vs N usually wins.
- Even when the position was blocked, the bishops would hold the draw comfortably by defending the bases of their pawn chains and swapping B for N where necessary.

Jerry

Thanks Jerry.

Really a great contribution!
I think here elephantiasis would not be true very much, as a quantity of lower power pieces would influence elephantiatically only enemy pieces of bigger strength. One of the advantages of bishops that I noticed is that they are easily traded for knights. If I had to set a single rule for playing the Bs in such a position, it would be to retain equal number of bishops of both colours whenever possible, so if the bishop side starts white, I would look to exchange first a light-squared bishop.

Thanks again.