user9286: Question: Title question, basically: do engines have a larger advantage over a human at long or short time controls? Have any studies been done on this?

Context for the question: On a reddit thread yesterday someone pointed out that Andrew Tang beat Leela in an ultrabullet game around four years ago. I was astounded by this -- I would not have thought this possible. (Leela was rated around 3250 on Lichess at the time, so she had been trained quite a bit there) I mentioned this to a buddy of mine, and his contention was that humans will perform better against engines at shorter time control. I thought that was flat out wrong, but set out to prove that point.
Unfortunately, I was not able to find much in the way of hard data. This best I could find was this experiment done by the folks (guy?) who runs FGRL that compares search depth against time. It seems that doubling the amount of thinking time approximately increases the search-depth by 2-ply. I have no idea how search-depth corresponds to playing strength -- the best I could find was this paper from 2013 that suggests that an increase in search depth of 2-ply is an increase in playing strength of approximately 120 rating points.
So, my best guess at this point is that doubling the amount of thinking time increases the engines rating by around 120 rating points. When I made the argument that engines have a bigger advantage at shorter time controls, I did not expect a 2-ply increase in search depth to increase the playing strength by 120 rating points, I expected it to be considerably lower.
Grandmasters also play exceptionally well at short time controls. How much do they gain by doubling the time. Is it 120 rating points? I don't know. Do you? This is what made me doubt my initial conclusion, and prompted this question.
Is the 120 rating point increase in computer playing strength by doubling its thinking time a reasonable conclusion?

user17100: This is kind of hard to answer because of how much better computers are than humans at all time controls, but according to https://chesspro-ru.translate.goog/guestnew/looknullmessage/?themeid=54&id=15&page=24&_x_tr_sl=ru&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=wapp, there was a 100 game match between SF11 and Fruit, where SF had 8 seconds per game + .04 seconds per move compared to 140 minutes per game + 40 seconds per move for fruit. With these settings, SF was about 150 elo stronger than fruit, which is roughly super-GM strength. Since then, SF has gained approximately https://github.com/official-stockfish/Stockfish/discussions/3628#discussioncomment-1047728, so SF at 1/4th second per game should be roughly the same strength as Magnus at a few hours per move.

user15223: Historically, the answer is "no". Computers beat humans at blitz well before they beat humans at classical chess (example).
Humans seldom play serious matches with a time handicap, so I'm not aware if there are statistics on how much elo a player gains by having 120 more minutes. With computers, the allocated time is less important than the depth it searches to - the difference between letting a computer think for 2 days vs. 1 day per move is much smaller than letting a computer think for 10 seconds vs. 5 seconds per move.
If you look at depth, then the elo gain with increasing search depth is tremendous. It depends on the engine, but an order of magnitude estimate for going one move deeper is a couple hundred elo.

9286: <p><strong>Question:</strong> Title question, basically: do engines have a larger advantage over a human at long or short time controls? Have any studies been done on this?</p>
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<p><strong>Context for the question:</strong> On a <a href="https://old.reddit.com/r/todayilearned/comments/sj23vu/til_no_human_has_beaten_a_computer_in_a_chess/" rel="nofollow noreferrer">reddit thread</a> yesterday someone pointed out that <a href="https://www.youtube.com/watch?v=FZVKvcKB_To" rel="nofollow noreferrer">Andrew Tang beat Leela</a> in an ultrabullet game around four years ago. I was astounded by this -- I would not have thought this possible. (Leela was rated around 3250 on Lichess at the time, so she had been trained quite a bit there) I mentioned this to a buddy of mine, and his contention was that humans will perform better against engines at shorter time control. I thought that was flat out wrong, but set out to prove that point.</p>
<p>Unfortunately, I was not able to find much in the way of hard data. This best I could find was <a href="http://fastgm.de/ratio-tc-depth.pdf" rel="nofollow noreferrer">this experiment</a> done by the folks (guy?) who runs FGRL that compares search depth against time. It seems that doubling the amount of thinking time approximately increases the search-depth by 2-ply. I have no idea how search-depth corresponds to playing strength -- the best I could find was <a href="http://web.ist.utl.pt/diogo.ferreira/papers/ferreira13impact.pdf" rel="nofollow noreferrer">this paper</a> from 2013 that suggests that an increase in search depth of 2-ply is an increase in playing strength of approximately 120 rating points.</p>
<p>So, my best guess at this point is that doubling the amount of thinking time increases the engines rating by around 120 rating points. When I made the argument that engines have a bigger advantage at shorter time controls, I did not expect a 2-ply increase in search depth to increase the playing strength by 120 rating points, I expected it to be considerably lower.</p>
<p>Grandmasters also play exceptionally well at short time controls. How much do they gain by doubling the time. Is it 120 rating points? I don't know. Do you? This is what made me doubt my initial conclusion, and prompted this question.</p>
<p>Is the 120 rating point increase in computer playing strength by doubling its thinking time a reasonable conclusion?</p>
 17100: <p>This is kind of hard to answer because of how much better computers are than humans at all time controls, but according to <a href="https://chesspro-ru.translate.goog/guestnew/looknullmessage/?themeid=54&amp;id=15&amp;page=24&amp;_x_tr_sl=ru&amp;_x_tr_tl=en&amp;_x_tr_hl=en-US&amp;_x_tr_pto=wapp" rel="nofollow noreferrer">https://chesspro-ru.translate.goog/guestnew/looknullmessage/?themeid=54&amp;id=15&amp;page=24&amp;_x_tr_sl=ru&amp;_x_tr_tl=en&amp;_x_tr_hl=en-US&amp;_x_tr_pto=wapp</a>, there was a 100 game match between SF11 and Fruit, where SF had 8 seconds per game + .04 seconds per move compared to 140 minutes per game + 40 seconds per move for fruit. With these settings, SF was about 150 elo stronger than fruit, which is roughly super-GM strength. Since then, SF has gained approximately <a href="https://github.com/official-stockfish/Stockfish/discussions/3628#discussioncomment-1047728" rel="nofollow noreferrer">https://github.com/official-stockfish/Stockfish/discussions/3628#discussioncomment-1047728</a>, so SF at 1/4th second per game should be roughly the same strength as Magnus at a few hours per move.</p>
 15223: <p>Historically, the answer is &quot;no&quot;. Computers beat humans at blitz well before they beat humans at classical chess (<a href="https://en.wikipedia.org/wiki/Human%E2%80%93computer_chess_matches#Anand%E2%80%93REBEL_(1998)" rel="nofollow noreferrer">example</a>).</p>
<p>Humans seldom play serious matches with a time handicap, so I'm not aware if there are statistics on how much elo a player gains by having 120 more minutes. With computers, the allocated time is less important than the depth it searches to - the difference between letting a computer think for 2 days vs. 1 day per move is much smaller than letting a computer think for 10 seconds vs. 5 seconds per move.</p>
<p>If you look at depth, then the elo gain with increasing search depth is tremendous. It depends on the engine, but an order of magnitude estimate for going one move deeper is <a href="https://en.wikipedia.org/wiki/Belle_(chess_machine)#Performance_Analysis" rel="nofollow noreferrer">a couple hundred elo</a>.</p>
