If you win a rematch, it doesn't "undo" a loss in the first game. If both you and your opponent have played a lot of games and you have essentially equal ratings, then the points gain from your win in the second game will be close to the decrease from your loss in the first game.
However, suppose you outrate your opponent by 200 points. If you lose the 1st game, your rating will drop quite a bit for losing to a lower rating. If you then win the second game, your rating will climb only a little bit, because you have only beaten a lower rating. Your net change after a loss and a win will be a lower rating.
Conversely, if you are the lower rated person, the initial loss will not knock much off of your rating. If you then get a win in the rematch, the points you get from beating someone much higher than you will be many more thanthose you lost, and your net change after a loss and a win will be a higher rating.
Playing a rematch is no different than playing someone else with the same (new) rating as your opponent in the first game.
Hi everybody, If i request a rematch, that means I can recover the lost points of this lost game? thanks for your answers, good holydays!