I’ve found that to beat Nelson, you have to be unconventional. Watch out for his queen and knights. With a lot of these bots, just go after his queen. Keep attacking her and he will give her up. I’m not an expert beating Nelson but he does make glaring mistakes from time to time.
One of my games against him to illustrate:
1. e4 e5 2. Qh5 Nf6 3. Qd1 Nc6 4. d3 Nd4 5. Qd2 d6 6. Nf3 d5 7. Nxe5 dxe4 8.
dxe4 Nxe4 9. Qd1 f6 10. Bc4 fxe5 11. O-O Be6 12. c3 Bxc4 13. cxd4 Bxf1 14. Kxf1
Bb4 15. dxe5 Qxd1# 0-1
Here’s an example when I got his queen:
1. d4 e5 2. e3 Qh4 3. Nf3 Qe4 4. Bd3 Nc6 5. Bxe4 Nge7
I play the Vienna game with White against Nelson sometimes. He brings his Queen to h4 on the second move, so I can't play the usual pawn f4, and play 3.Nf3 instead. The key is to keep kicking his queen around with the two knights, and eventually he will mess up and lose the Queen, or you can at least fork his King and a rook. If you leave his Queen alone, Nelson will develop a few other pieces, and then he starts to play better.
That Renaissance dude Raphael is an improved version of Nelson. He brings out the Queen to quick to, but doesn't blunder so much.