Bogo-Indian Defense: Retreat Variation
1.d4 Nf6 2.c4 e6 3.Nf3 Bb4+ 4.Bd2 Be7
What Is The Retreat Variation?
The check on move three asks White a question, and 4.Bd2 answers it. You retreat to e7, keeping every piece on the board, and leave White's bishop stranded on d2, where it blocks the queen and attacks nothing. The trade-off is plain: you have spent an extra tempo to reach e7, and in return White's bishop sits on d2 rather than on a square it would have chosen.
From here, play d5 for a solid Queen's Gambit structure, or d6 followed by e5. White needs Nc3 and e4 to claim the center, and that is where games are decided: strike back with c5 or e5 before the big center rolls forward, and White is left defending loose pawns with a bishop that never joined the game.
How Do You Play Against The Bogo-Indian Defense: Retreat Variation?
There is no reliable data for this position, so treat what follows as understanding rather than measurement. Black has checked on b4 and then retreated the bishop to e7, spending two moves to place a piece where it could have gone in one.
Two tempi is a real advantage in a closed position and a decisive one in an open position, so open the position. Play e4 if you can get it in, or c5 and d5 to fix the structure while Black is still catching up. The Bogo-Indian relies on solidity, and solidity is only worth something when the defender has finished developing. Push before that happens and the extra moves count.