Jermaine is currently one of the NBA Playoffs top shot blockers and it shouldn't be a surprise. Despite only playing 24 regular season games he was 4th on the team in blocks at 30. O'Neal is only averaging 5 points, 4 rebounds, and 2.5 blocks per game, and while his postseason numbers don't jump off the board, if you watch the games his presence is undeniable.
As the last line of defense JO contests every shot near the rim, even if he doesn't get the block he often changes it at the last second. It's hard to expect a player to help on the shot and come up with the defensive rebound after the miss, that'w why Coach Doc Rivers has challenged his players to get back on the glass and crash the defensive boards. With O'Neal swatting at shots and KG gathering the misses, Boston is starting to figure it out.
In the first round against NY The Celtics defense showed glimpses of what it could be. Rondo was pressuring the ball, Ray was helping while still making sure to get out and contest shots, Pierce provided the game with a little bit of everything, Garnett locked it down in the fourth quarter, and Jermaine O'Neal was protecting the rim against anybody who was lucky enough to sneak through.
JO also providing that playoff toughness that everyone was looking for. He battled down low, delivered hard fouls, and got into it with anyone that took exception. What more can you ask from a center who's starting alongside four All-Stars?
In the 2nd round Boston will most likely be facing the Miami Heat. Just last season JO was a 2nd or 3rd option behind MVP Candidate Dwayne Wade. Jermaine started 70 games and posted a career high in FG% (52%). Alongside Wade O'Neal anchored a defense that was statistically one of the best. The most amazing part of the 2010 Miami Heat is that other than Wade and JO they had hardly any players that were known as great individual defenders.
Quentin Richardson is a notoriously poor defender, Michael Beasley has since shown that defense difficult for him to grasp, and no one would ever crown Carlos Arroyo as a lock down defensive point guard. Jermaine O'Neal almost single handedly propelled the Heat's defense to be the 2nd best defensive unit in the NBA.
People can mock Jermaine for him being injury prone, they can mock him for contributing basically zero this season, they can even give him grief about his off court business ventures while away on rehab, but one thing they can't do is deny the fact that 75% of Jermaine O'Neal is one hell of a 5th option on a team with 4 All-Stars.
It even seems as if Doc Rivers has feels the same exact way, there were crucial 4th Quarter moments in that Knicks series where he elected to roll with JO as opposed to Glen Davis, and while that's a whole different argument, it's hard for anyone to disagree with the Doctor.