I have 7 taps. I always keep this:
1. Session Stout/Porter or something dark
2. IPA
3. Specialty IPA(Black IPA, Red IPA, Milkshake IPA....)
4. Lager(Helles, Pilsner, Dunkel, cream ale)
5. Specialty Lager(cucumber, coffee blonde/lager, or other fruit beers....)
6. Barrel Aged Imperial Stout...