One of the biggest advantages the Los Angeles Lakers had over the Boston Celtics before the 2010 NBA Finals began was their length in the post, mainly consisting of Andrew Bynum, Pau Gasol and Lamar Odom.
Bynum was the key, because although Gasol is a true seven footer and Odom is long in his own right, neither player is as physical as Bynum in the paint, and neither player is as strong.
The Boston Celtics have tough, physical players in Kevin Garnett, Kendrick Perkins and Glen Davis, but none of those players could out-muscle Bynum in the paint once he got position, and his height advantage made it easier to shoot over them.
Through the first three games of the series Bynum began to establish himself as a dominant player on both ends of the court, but a lingering knee issue could hamper his playing time, and the Lakers' chances for a repeat.
The pain from Bynum's partially-torn meniscus limited his playing time in Game Four, and for the first time in the series, the Celtics completely dominated the Lakers in the paint.
Bynum only played 12 minutes and the Lakers' only lost the battle of the boards 41-34, but they were out-rebounded 16-8 on the offensive glass, and Odom and Gasol only had one offensive rebound a piece.
In fact, both Gasol and Odom spent much of the fourth quarter getting out-hustled and pushed around by the shorter, but stouter Davis who controlled the paint in the end of the game.
It was a stunning reversal for Gasol who had all but shed his image as a soft player during this series, but now faces new questions about his physical fortitude in the wake of Davis' abuse.
It's clear the Celtics would rather face a combination of Gasol and Odom rather than one featuring Bynum, and now the Lakers must adjust against a Boston team who may smell blood in the water.
Bynum had no elevation in his legs during the brief moments he was in the game, and if he is to be a factor in this series, the best option the Lakers may have is to rest him in preparation for Game Six.
Lakers' coach Phil Jackson should consider sitting Bynum in Game Five, and give Odom and Gasol the opportunity to prove their poor performances in the paint in Game Four were an aberration.
The only problem with this strategy is the Lakers have been eerily similar to their Finals' team of 2008 when Bynum has been out of the game, and they can ill-afford to let Boston build on their momentum from Game Four.
There were times over the first three games where the Celtics' frontline seemed at a loss on how to deal with the Lakers' size up front, but in Game Four you could see Davis, Perkins and Paul Pierce growing increasingly comfortable attacking the rim.
Gasol is a decent defensive player but he is not as physically imposing as Bynum, and his slender build makes him more prone to bullying in the post, such was the case last night.
There were numerous reasons the Celtics were able to tie the series last night, such as key Lakers' turnovers, missed technical free throws from Derek Fisher and Kobe Bryant, and the emergence of the Boston bench.
But the main reason the Lakers lost can be traced to the inability of Gasol and Odom to get critical defensive stops and prevent the Celtics from crashing the offensive boards.
This is a direct result of Bynum's absence from the Lakers' line-up, and if he is unable to contribute significantly for the remainder of the series, it could set an entirely different tone for Los Angeles.