Base stats are the stats for a level 20 ('adult') Pokemon.
HP in GURPS = literal. The lowest HP is 1. An adult Bulbasaur has HP 45.
Atk: PST is halved. Lowest Atk on record is 5. Atk 49 = ST 24. PDmg = 2d+1 thr, 4d+2 sw.
Def: SDR is 1/5. Lowest Def on record is 5. Def 49 = SDR 9.
SAtk: SST is halved. Lowest SAtk on record is 10. SAtk 65 = ST 32. SDmg = 3d+1 thr, 6d-1 sw.
SDef: SDR is 1/5. Lowest SDef on record is 10. SDef = SDR 13
Spd: Base Speed is 1/8. Lowest Spd on record is 5. Spd 45 = Base Spd 5.5
Base Move is 5.
IQ starts at 8. Evolved forms gain +2 per evolution. Certain Pokemon have exceptional intelligence.
DX starts at 12. Possibly a small boost based on speed? Probably not, that would imbalance things.
HT and Will are equal to 17 - (CatchRate/10), rounded up. A catch rate of 5 is HT 16. 15 is HT 15, 25 is HT 14, 35 = HT 13, 45 = HT 12, etc.
Pokemon stats are for a standard adult (Lev 20). Children are roughly 50% of these stats or less (Lev 10 or less); champions are often much higher. Children are level 1 to 5. Lvl 1 = 50% stats, Lvl 2 = 60% stats, Lvl 3 = 70%, Lvl 4 = 80%, Lvl 5 = 90%.
Pokemon reach 'levels' every 10 CP. Level 1 - 10 CP to spend as they see fit. Level 100 - 1000 CP beyond the ordinary adult package.
PP are 40 ER per move for a total of 160 ER.