No, back capping does not work if your team has 1/2 of a brain, collectively.
Enemy team sends three top, and one to your mid. Your team sends four top after capping mid.
Enemy team loses the 4v3 and windmill, your team leaves two players at Windmill and two to take back middle. Your duo at Windmill can defend the oncoming 3v2 because of tower.
Your team takes back middle and sends one more top to help defend windmill, while the remaining (highly mobile) player roams. They don't have to kill the backcapper, only poke to stop them from actually capping.
One person on each team is now tied up doing nothing, and your team has the advantage at Windmill because it's 3 vs. 3+Tower...
All boots of mobility Phantom Dancers