In this line of the 3 knights opening

[fen "start"]

1. e4 e5 Nf3 Nc6 Nc3 Bc5 Nxe5 Nxe5 d4 Bd6 dxe5 Bxe5

the best continuation according both to my engines and to databases is 7. Bd3. Why? For instance, can anyone explain why that's better than 7. Be2 or 7. Bc4?

Below some of the reasons I found by myself, but I would love to have confirmation or hear more:

• If the pawn on e4 moves, the bishop would attack the h6 square which might be helpful for a mating attack in case black castles king-side. 7. Be2 doesn't attack any important square
• 7. Bc4 would attack f6, but the bishop is undefended on c4 and might become a target
• 7. Bd3 gives extra protection to the e4 pawn (useful in case white needs to move the knight on c3), neither 7. Bc4 nor 7. Be2 does that

In this line of the 3 knights opening

[fen "start"]

1. e4 e5 Nf3 Nc6 Nc3 Bc5 Nxe5 Nxe5 d4 Bd6 dxe5 Bxe5

the best continuation according both to my engines and to databases is 7. Bd3. Why? For instance, can anyone explain why that's better than 7. Be2 or 7. Bc4?

Below some of the reasons I found by myself, but I would love to have confirmation or hear more:

• If the pawn on e4 moves, the bishop would attack the h7 square which might be helpful for a mating attack in case black castles king-side. 7. Be2 doesn't attack any important square
• 7. Bc4 would attack f7, but the bishop is undefended on c4 and might become a target
• 7. Bd3 gives extra protection to the e4 pawn (useful in case white needs to move the knight on c3), neither 7. Bc4 nor 7. Be2 does that

In this line of the 3 knights defense

[fen "start"]

1. e4 e5 Nf3 Nc6 Nc3 Bc5 Nxe5 Nxe5 d4 Bd6 dxe5 Bxe5

the best continuation according both to my engines and to databases is 7. Bd3. Why? For instance, can anyone explain why that's better than 7. Be2 or 7. Bc4?

In this line of the 3 knights opening

[fen "start"]

1. e4 e5 Nf3 Nc6 Nc3 Bc5 Nxe5 Nxe5 d4 Bd6 dxe5 Bxe5

the best continuation according both to my engines and to databases is 7. Bd3. Why? For instance, can anyone explain why that's better than 7. Be2 or 7. Bc4?

Below some of the reasons I found by myself, but I would love to have confirmation or hear more:

• If the pawn on e4 moves, the bishop would attack the h6 square which might be helpful for a mating attack in case black castles king-side. 7. Be2 doesn't attack any important square
• 7. Bc4 would attack f6, but the bishop is undefended on c4 and might become a target
• 7. Bd3 gives extra protection to the e4 pawn (useful in case white needs to move the knight on c3), neither 7. Bc4 nor 7. Be2 does that