9 defense:
1-2 hp: die to a wild L6-9 zubat (255/256+shake) or meowth/starmie if no zubats somehow
3-8 hp: die to sandshrew (255/256)
9-10 hp: die to brock's geodude (95%)
11-18 hp: die to rocket's meowth (~2/3 per turn, 95% of 2/3 for 18hp exactly)
19+: die to starmie (~56% per turn until xdefend used, then 75% thereafter)

10 defense:
1-2 hp: die to a wild L6-9 zubat (255/256+shake) or meowth/starmie if no zubats somehow
3-8 hp: die to sandshrew (255/256)
9 hp: die to brock's geodude (95%)
10-16 hp: die to rocket's meowth (2/3 per turn)
17+: die to starmie (~56% per turn until xdefend used, then 75% thereafter)

11 defense:
1-2 hp: die to a wild L6-9 zubat (255/256+shake) or meowth/starmie if no zubats somehow
3-7 hp: die to sandshrew
8 hp: die to brock's geodude (95%)
9-15 hp: die to rocket's meowth (2/3 per turn)
16+: die to starmie (~56% per turn until xdefend used, then 75% thereafter)