What I meant in the original post was that how would using the Martingale be better than using the Kelly% when it comes to money managing SNG buy-ins?

To simplify things, let's take the case of a 66% ITM (aka 20% ROI)HEADS UP SNG player. He plays 5+5. Once he loses, he plays 5+5 again. Once he loses, he moves up to 11. Once he loses, he moves up to 33. Once he loses, he plays 33 once again. Once he loses, he plays 55. Once he loses, he plays 109. Once he loses, he plays 215. That's 8 loses in a row. There's no way a 66% ITM (aka 20%ROI) heads up player would lose 8 games in a row.

How would this system be better or worse than using the Kelly to make money management decisions?