This was an extremely ugly and almost unwatchable game at times, but that's the kind of game the Bulls need to keep staying alive in this series. No matter what the issues have been in the past 3 games with their offense, especially in fourth quarters, if the Bulls can keep an opponent under 70 points that's a good way to create margin for error on the other end.
And indeed the defense was fantastic. They held the Sixers to 32% shooting (2-11 from three), and completely shut down their guard play, as Spencer Hawes (4-9) and Lavoy Allen (4-7) had a couple of the better nights on the team. They were trying to maintain the aggressiveness and running when they could, but the Bulls did a much better job getting back on defense, forcing them either into a rushed shot or their 14 turnovers. The poor shooting is something we can expect from Philly, but the turnovers make their offense completely unworkable.
And there's a lot of credit to go around for how hard the Bulls defense made things, most of it going to the bench mob. Taj Gibson and Ronnie Brewer were everywhere in this game, getting to those 50/50 balls (though they were outrebounded as a team yet again) and proving that the effort gap could stay on their team's side. Asik and Lucas contributed to that overall dominance in that intangible category, but Brewer had 3 steals, and Gibson had 4 blocks in the 2nd quarter alone. Unfortunately Gibson also became the latest Bull to be felled by injury, spraining his ankle pretty badly in the second half. Taj did return to the game, and though it brought some emotion, it was with little else: Both his injury and return didn't look as bad as what Joakim Noah suffered in game three, but we've seen similar sprains in the past where a player can come back in that game but is unable to the next after a night of swelling.
Meanwhile Brewer shook up the wing rotation for Tom Thibodeau, logging 29 minutes which was more than Hamilton and Korver combined. Particularly surprising after it looked to be Brewer who was exiting the rotation (and likely the team) after his DNP in game three. But it just never looked to be the type of game for the more offensive-minded wings. CJ Watson (who stunk overall) struggled to get Rip the ball in the right spot, and Rip compounded things by forcing his way into some tough looks and continuing his defensive struggles.
Maybe Thibodeau figured this just wasn't going to be a game for the offensive playbook, and it turned out the Bulls had just enough from Carlos Boozer and Luol Deng. And yes, it was in the fourth quarter as well. Boozer had what has become a routine night for him in this series: solid production on slightly-sub-mediocre efficiency (19pts on 20 shots), good assists and rebound totals balanced out by his usual dose of turnovers (5) and defensive miscues. He may not be 'taking over', because really can't, even against the Sixers. But Boozer is recognizing how much the team needs him to score (otherwise you'll see way-less-than-mediocre efficiency) and taking it upon himself to take the shots.
Luol Deng started as the game's hottest player (it didn't take much), relentlessly driving to the basket and teetering the edge of effective and reckless. He wound up closing with an absolute flurry of three clock-beating, ridiculous three-pointers. It was the first game of the series where Deng thoroughly out-produced Andre Iguodala (a woeful 4-19), and thankfully we didn't have to see what would've happened if those 3s didn't go in and the game tightened up. Especially in a game where their two best shooters barely helped, the Bulls had to win this one through defense and hustle, and the bench mob gave them the edge in each.