Hi,

Let me bring some reasonable arguments why your cheater detection is not working correctly and delivers false positives like myself.

1. My opponent jerry_123 in the two suspicious games beat me 4 times before. If you look at those 4 games, I blundered and resigned in all of them when I saw that I was going to play with material disadvantage. I could feel though that I was better and can beat him so we kept playing and when I pulled myself together and stopped blitzing out moves those two games happened.

2. Now if we take a closer look at those two games, we can see that my moves are very simple. In fact, in every move that is not obvious development I attack something or trade pieces. My opponent makes wrong trades and does not defend against my attacks hence it is unavoidable that the engine rating is strictly monotonic in my favor. The two checkmates ending these games can be seen from miles by every player rated above 1000.

3. I played over 500 games on lichess and there are only these 2 suspicious games you brought as example. This means that I'm getting banned because of less than 0.4% of my games ever played on lichess. This seems too harsh especially considering that I played very naturally in those games.

4. The two example games consist of only 20 and 23 moves, respectively, and they end with checkmate. Theoretically, this low number of moves could be the preparation of any player and thus very closely resemble engine moves. While this is not the case here (see 2.), it should be taken into account when designing a cheater detection system.

5. Finally, somewhat backing up on 2., I recently played another "perfect" game on chess.com https://www.chess.com/live/game/2624408143. I think it has similar motives as the first example game (using the pin on the knight). According to the post-game analysis I played the best move 100% time. Needless to say: I did not cheat! This just happens sometimes when you opponent lets you play your every plan.

Please consider these points and remove the ban from my account as I love playing on lichess. Or at least reply something.

Best regards,
xtibis
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On Fri, Feb 16, 2018 at 2:55 AM Tibor Keresztfalvi <xtibis@gmail.com> wrote:
Dear fellow Chesslover

These are two nice victories of mine. I didn't cheat in any of them. (By the way, I think it would be pretty hard to evaluate any position in a bullet game.) Please remove the ban from my account as I didn't do anything wrong by beating a weaker player twice.

Kind regards,
xtibis


On Fri, Feb 16, 2018 at 1:21 AM Lichess Contact <contact@lichess.org> wrote:
https://lichess.org/DGDMZvxN
https://lichess.org/XpWGNjMD/black

On Thu, Feb 15, 2018 at 3:07 PM, Tibor Keresztfalvi <xtibis@gmail.com> wrote:
Hi,

I did NOT cheat! Also, I feel offended by such accusations without any proof... I'm taking lectures with one of your coaches and playing rapid games instead of blitz and bullet so with more time to think I get to higher ratings. If this fact is already proof enough for cheating than I guess there is nothing else for me to do than stop playing on lichess.. Would be very sad though.

Sent from my iPhone

On 15 Feb 2018, at 19:33, Lichess Contact <contact@lichess.org> wrote:

Hi,

It's because you cheated.

On Thu, Feb 15, 2018 at 9:56 AM, Tibor Keresztfalvi <xtibis@gmail.com> wrote:
Good day,

As of today afternoon I keep getting paired with players that have the warning "This player uses computer chess assistance!" on their profile and are much higher rated than I am, or are playing their placement games. Obviously I have no interest in playing such players and I don't understand why I am suddenly only getting paired with these players. Normally I had to wait a couple of seconds to get paired and play. Now I have to wait forever just to get paired up with one of these guys. Could you please fix this?

Best regards,
xtibis