Funny thing is a 1300 Elo player stands no chance against a 2700 GM even if that GM has only one minute per game and a 1300 player has as much time as he/she wants! That's because the GM will also compute and evaluate positions while a 1300 player is thinking. Even if a 2700 player plays blindfolded, a 1300 stands no chance
Well, according to the Elo system a 200 points lower player has 25% odds of winning. Here it is 1400 points. The math is simple: 0.257≈0.00006 or 0.006 %. However, I think this math won't work because when you have such a huge difference it will be further augmented by these 1400 points. So much so that the odds are less than one out millions (or something of that magnitude) under standard time control. This 0.006% (1 win out of 60.000) may only work in bullet, I guess, where a strong GM might still blunder. However, a low Elo player must be no slowpoke in bullet or he/she won't convert even a serious blunder against a GM. All this math and reasoning will collapse and be no longer valid if you pair a 1300 Elo player with a 2500 engine. A human 1300 will stand a chance of probably less than one out of a billion!!! And of course even less than that in a bullet game against an engine
This math must also be no good because if they play so many games a 1300 player will learn a lot along the way, improving his/her Elo rating