when you lost do yourself a favor start a new game and try to do better
you mean “when you are losing”.
One could also say "When you are lost, do yourself a favor. Start a new game and try to do better."
Two missing capital letters, a missing linking verb, a missing comma, and two missing periods, by a native of an English speaking country.
It would be foolish to resign against him!
when you lost do yourself a favor start a new game and try to do better
If I know my American opponent's English is this bad, I wouldn't resign either!
In correspondence, I'd resign.
In rapid, over the weekend, I dropped a Knight as Black about 15 moves in and won. I could tell from the cheap shot nature in his play that he would have no clue what he was doing still, and he didn't! Resignation or not depends on the scenario.
In blitz, the clock is part of the game. On rare occasion I do resign, but you better have won large amounts of material and have over 2 minutes on the clock.