Going down to 10 means it's very difficult to win a game but I don't think it really affects your odds of losing.
Chelsea shouldn't be losing 3-1 at home to Brighton just because they went down to 10 for the last half an hour.
Maresca will be an elite manager but he does need to stamp this out. The top coaches don't lose that game.
I would say though, this is the result of persistently buying U21 players. Their squad on Saturday was;
Sanchez - 27
James - 25
Chalobah - 26
Hato - 19
Cucurella - 27
Santos - 21
Caicedo - 23
Fernandez - 24
Estevao - 18
Pedro - 24
Neto - 25
Acheampong - 19
Gittens - 21
Garnacho - 21
George - 19
Guiu - 19
Gusto - 22
Jorgensen - 23
Lavia - 21
Badiashile - 24
That team clearly needs a few experienced leaders to see them through games like that.