[eth0up]

In my opinion, there is no acceptable handicap system for chess; its symmetry isn't conducive. It is also something that is almost never done - I've never seen a handicap (beyond time and color) used in any chess club. Allotting more time to the weaker (and less to the stronger) player is probably the best method of balancing skill discrepancy. This is one of the reasons I abandoned chess for go (baduk, weichi, igo, etc.), where the handicap system is fully functional up to 9 additional stones (pieces) for the weaker player. The gameboard sizes can range from 19x19 to 5x5 (refers to the intersecting lines within grid). While this system is almost perfect in go, it is at best a blemish to the game in chess. However, loser's chess can be quite entertaining. https://en.wikipedia.org/wiki/Losing_chess

[Razengan]

I think a good handicap system for chess would be too allow [unlimited] undos to the weaker player but no undos to the stronger player.

That would allow the newb to quickly try different strategies and see their outcomes right away, enabling them to learn faster.