Any attempt to access Talkchess results in this message:

Forbidden
You don't have permission to access /forum3/viewtopic.php on this server.

It was accessible till yesterday.

H.G.Muller wrote:I always use the condition depth > 0. I.e. I don't do null move in QS (d <= 0), but do it for any higher depth. At d=1, 2 and 3 the reply is QS.

This is reasonable. I wonder why the cpw code in the original post uses the condition depth>2 .

As in many other programs, minimum depth for null move is 2 for crafty 24.1.

if (do_null && !pv_node && depth > 1 && !in_check &&
TotalPieces(wtm, occupied)){
............code.....
if (depth - tdepth - 1 > 0)
value =
-Search(tree, -beta, -beta + 1, Flip(wtm), depth - tdepth - 1,
ply + 1, 0 ...