I've never tried Al only or NL only so I set up these fun leagues to give it a try. H2H, autodraft, free league, 12 team (I know, a lot of you hate autodraft but I live in the country and my IP keeps crashing at the worst times and it's hard to get back online), std Yahoo scoring, min 10 IP, std Yahoo positions (with the exception of 7 BN and 3 IL)
AL only league: Yahoo #262650
NL only league: Yahoo #262680
No password required.
Still holds the MLB record for Grand Slams with 23