Overprotection and prophylaxis My understanding (and I may be wrong there) is that prophylaxis is a wider concept than overprotection, and so there are some prophylactic moves that don't have anything to do with overprotection (like advancing one of the castling pawns to defend against 8-th line mates).

I also think I get the point of overprotection in term of enhanced piece mobility. However when it comes to prophylactic moves not involving overprotection (like the pawn advanced discussed above) is it really just a fancy name for not having the time to find a way to take the initiative?
However when it comes to prophylactic moves not involving overprotection (like the pawn advanced discussed above) is it really just a fancy name for not having the time to find a way to take the initiative?


Not quite! Sometimes, in order to fight for the initiative or even maintain the initiative, you have to make prophylactic moves to minimize your opponents counterplay or initiative. Have you considered that the move 5...a6 in the Sicilian Najdorf is actually a prophylactic move? 

 [FEN "rnbqkb1r/pp2pppp/3p1n2/8/3NP3/2N5/PPP2PPP/R1BQKB1R b KQkq - 0 5"]

 1...a6!? 


The move a6 prevents (prophylaxis) White from giving a check on b5 in the main line of the Najdorf after 6...e5. It also prevents White from playing the dangerous Keres attack with 6. g4, which is normally playable after Black plays 5...e6. 

Now let us consider what happens if Black doesn't play a6 and tries to "take the initiative" with 5...e5. 

   [FEN "rnbqkb1r/pp2pppp/3p1n2/8/3NP3/2N5/PPP2PPP/R1BQKB1R b KQkq - 0 5"]

   1...e5?! 2. Bb5+! Bd7 (2...Nbd7 3. Nf5!) 3. Bxd7+ Qxd7 4. Nb3


In this final position, White is already slightly better. He has exchanged Black's good light-squared bishop. Black is now left with a bad bishop on f8 and a hole on d5, with only the knight on f6 to cover it and no light squared bishop. Overall, Black's idea to press on with e5 in an attempt to take the initiative backfired because of a lack of prophylaxis. 

Compare that position with this position which occurs in a popular line of the Sicilian Najdorf. 

   [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

   1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be2 e5 7. Nb3 Be6 8. Be3
   Nbd7 9. O-O Be7 10. f3 O-O 


Here, Black securely guards the d5 square with Bishop and Knight and his bishop on e6 is much stronger than its counterpart on e2. If white attempts to occupy the hole on d5, Black simply exchanges knights, eliminates the hole on d5 and keeps the position in the balance. Note that the presence of the bishop on e6 prevents White from recapturing with the queen and maintaining the hole on d5. 

    [FEN "r2q1rk1/1p1nbppp/p2pbn2/4p3/4P3/1NN1BP2/PPP1B1PP/R2Q1RK1 w - - 0 11"]

    1. Nd5 Nxd5 2. exd5 Bf5


The reason why the Najdorf Sicilian is one of the most popular openings is because it allows Black to fight for the initiative instead of simply trying to neutralize White's initiative. That's all made possible by this naive looking prophylactic move 5...a6!