SudoTrainer's Brock calculations

Geodude
        () is crit
15 Def: 7 - 9 (12 - 15)
16 Def: 6 - 8 (11 - 14)
17 Def: 6 - 8 (11 - 13)

Onix
        () is crit      | - 2 Def           | - 4 Def
16 Def: 6 - 8 (11 - 13) | 11 - 14 (11 - 13) | 17 - 21 (11 - 13)
17 Def: 5 - 7 (10 - 12) | 11 - 14 (11 - 13) | 17 - 21 (11 - 13)
18 Def: 5 - 7 (10 - 12) | 10 - 12 (10 - 12) | 17 - 21 (11 - 13)
19 Def: 5 - 7 (10 - 12) | 10 - 12 (10 - 12) | 15 - 18 (10 - 12)