Here's my list, and some reasons:Babe Ruth - changed the way the game was played. Jackie Robinson - his success changed who could play the game. (You might add Larry Doby as an entry here)Cap Anson - his influence changed who could not play the game. Shoeless Joe Jackson - his banishment cleaned up the game... even a superstar who looked like he played well wasn't above the law (and with that already established, I can leave Pete Rose off the list). Hideo Nomo - his success globalized scouting (and I might add, turned scouting into a fad) Ty Cobb - no particular reason, but he probably influenced the style of play more than anyone until Ruth came along, and may have been of the game's earliest great villains. Curt Flood- changed the finances of the game and broke the players free from indentured servitude.Nap Lajoie - legitimized the American LeagueBob Gibson. He forced baseball to lower the mound, and as a result, the game was taken away from the pitchers and given back to the batters, ushering in a whole new era. To me, THAT is impact on the game. Frank Robinson - When he was traded from Cincy to Baltimore, he reminded an entire league how to play baseball. The AL had settled into a "Wait for the three run homer" kind of league. When Frank joined the O's, he showed them that it was within the rules to go from first to third on a hit to right. He demonstrated that it was also "legal" to break up a double play. And he led by example, something Black players weren't supposed to do, with his fiery nature. He broke stereotypes on the field, that Blacks were "athletes" who only got by on "natural ability". Then, he showed that a Black man could not only manage a baseball team (and he is still doing that very well), but work in the front office as well. I know I said to limit responses to players only, but Frank's contributions to the game far transcended that. An arguement can be made that he took over where Jackie Robinson led the way and moved the banner farther forward. And for those reasons, he's on my list.I would have loved to have added Greenberg to my list. But the reasons mentioned above were more societal in nature than strictly baseball related.LaterEDITS: cleaned up typos