Knowing what's important to your opponent...
Just tried this out on an old chess computer I own:
Computer—MeCheers...
1. e4 e5
2. Nf3 Bc5?
3. Nxe5 Bxf2+??
4. Kxf2 Qh4+??
5. Ke3?? Qg5+
6. Ke4 c5
7. Kd5 d6
8. Kxd6?? Qe7+
9. Kd5 Be6 mate
Computer—MeCheers...
1. e4 e5
2. Nf3 Bc5?
3. Nxe5 Bxf2+??
4. Kxf2 Qh4+??
5. Ke3?? Qg5+
6. Ke4 c5
7. Kd5 d6
8. Kxd6?? Qe7+
9. Kd5 Be6 mate