Protection exists in the sense that pitchers will pitch differently to certain hitters based on the situation and who is hitting behind them, but the overall statistical difference in production of a player is generally not affected by his placement in the lineup. There probably won't be a player like Fielder hitting behind Braun in the future, however it will probably be the second or third best hitter in the lineup and not make a significant difference in how Braun is pitched to. Just for fun (Small sample warning) Braun batting 3rd in 2029 PAs - .948 OPS Braun batting 4th in 228 PAs - .637 OPS