kate/BadFish
1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-07-11 19:49:14 +00:00
Code Issues Releases Wiki Activity

Use average bestMoveChanges across all threads #2072

Browse source 
The current update only by main thread depends on the luck of
whether main thread sees any/many changes to the best move or not.
It then makes large, lumpy changes to the time to be
used (1x, 2x, 3x, etc) depending on that sample of 1.
Use the average across all threads to get a more reliable
number with a smoother distribution.

STC @ 5+0.05 th 4 :
LLR: 2.95 (-2.94,2.94) [0.50,4.50]
Total: 51899 W: 11446 L: 11029 D: 29424
http://tests.stockfishchess.org/tests/view/5ca32ff20ebc5925cf0016fb

STC @ 5+0.05 th 8 :
LLR: 2.96 (-2.94,2.94) [0.50,4.50]
Total: 13851 W: 2843 L: 2620 D: 8388
http://tests.stockfishchess.org/tests/view/5ca35ae00ebc5925cf001adb

LTC @ 20+0.2 th 8 :
LLR: 2.95 (-2.94,2.94) [0.00,3.50]
Total: 48527 W: 7941 L: 7635 D: 32951
http://tests.stockfishchess.org/tests/view/5ca37cb70ebc5925cf001cec

Further work:
Similar changes might be possible for the fallingEval and timeReduction calculations (and elsewhere?), using either the min, average or max values across all threads.

Bench 3506898
This commit is contained in:
xoto10 2019-04-03 08:35:55 +01:00 • committed by Marco Costalba
parent 0f63b35120
commit 1982fe25f8
2 changed files with 14 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

21
src/search.cpp
View file

@ -191,8 +191,11 @@ void MainThread::search() {
else
{
for (Thread* th : Threads)
{
th->bestMoveChanges = 0;
if (th != this)
th->start_searching();
}
Thread::search(); // Let's start searching!
}
@ -283,7 +286,7 @@ void Thread::search() {
Move lastBestMove = MOVE_NONE;
Depth lastBestMoveDepth = DEPTH_ZERO;
MainThread* mainThread = (this == Threads.main() ? Threads.main() : nullptr);
double timeReduction = 1.0;
double timeReduction = 1, totBestMoveChanges = 0;
Color us = rootPos.side_to_move();
std::memset(ss-7, 0, 10 * sizeof(Stack));
@ -294,9 +297,6 @@ void Thread::search() {
bestValue = delta = alpha = -VALUE_INFINITE;
beta = VALUE_INFINITE;
if (mainThread)
mainThread->bestMoveChanges = 0;
size_t multiPV = Options["MultiPV"];
Skill skill(Options["Skill Level"]);
@ -328,7 +328,7 @@ void Thread::search() {
{
// Age out PV variability metric
if (mainThread)
mainThread->bestMoveChanges *= 0.517;
totBestMoveChanges /= 2;
// Save the last iteration's scores before first PV line is searched and
// all the move scores except the (new) PV are set to -VALUE_INFINITE.
@ -459,7 +459,7 @@ void Thread::search() {
&& !Threads.stop
&& !mainThread->stopOnPonderhit)
{
double fallingEval = (306 + 9 * (mainThread->previousScore - bestValue)) / 581.0;
double fallingEval = (314 + 9 * (mainThread->previousScore - bestValue)) / 581.0;
fallingEval = clamp(fallingEval, 0.5, 1.5);
// If the bestMove is stable over several iterations, reduce time accordingly
@ -467,7 +467,10 @@ void Thread::search() {
double reduction = std::pow(mainThread->previousTimeReduction, 0.528) / timeReduction;
// Use part of the gained time from a previous stable move for the current move
double bestMoveInstability = 1.0 + mainThread->bestMoveChanges;
for (Thread* th : Threads)
totBestMoveChanges += th->bestMoveChanges;
double bestMoveInstability = 1 + totBestMoveChanges / Threads.size();
// Stop the search if we have only one legal move, or if available time elapsed
if ( rootMoves.size() == 1
@ -1101,8 +1104,8 @@ moves_loop: // When in check, search starts from here
// We record how often the best move has been changed in each
// iteration. This information is used for time management: When
// the best move changes frequently, we allocate some more time.
if (moveCount > 1 && thisThread == Threads.main())
++static_cast<MainThread*>(thisThread)->bestMoveChanges;
if (moveCount > 1)
++thisThread->bestMoveChanges;
}
else
// All other moves but the PV are set to the lowest value: this

4
src/thread.h
View file

@ -63,7 +63,7 @@ public:
size_t pvIdx, pvLast;
int selDepth, nmpMinPly;
Color nmpColor;
std::atomic<uint64_t> nodes, tbHits;
std::atomic<uint64_t> nodes, tbHits, bestMoveChanges;
Position rootPos;
Search::RootMoves rootMoves;
@ -85,7 +85,7 @@ struct MainThread : public Thread {
void search() override;
void check_time();
double bestMoveChanges, previousTimeReduction;
double previousTimeReduction;
Value previousScore;
int callsCnt;
bool stopOnPonderhit;