I used to think that until this season. One of the better SP in our league became available during this season's Free Agency period. multiple owners offered MAX deals ($20/m per season plus $10m Bonus) - he signed with the owner with the better pitching coach. According to a forum post, pitching coaches (pitching/bullpen) and ballpark (best pitchers park for pitchers) are tiebreakers. Club loyalty is also a factor if the player has played for 5+ years with a club.