Did former Lakers guard Derek Fisher invade Sessions' body, or is the current toast of Los Angeles really just that bad defensively?
Some Lakers fans have downplayed Sessions' obvious deficiencies on defense, but Parker's constant forays to the rim made that flaw hard to ignore.
Parker had many moments during his 29-point, 13-assist performance, but none may have been more memorable than his crossover move in the third quarter that left Sessions flat-footed and grasping at air while Lakers reserve Jordan Hill applauded from the bench.
It's kind of hard to believe that Sessions is not really a bad on-ball defender after that play.
If the playoffs started today and the seedings held to form, the Lakers would meet the Spurs in the Western Conference Finals, but they would have to beat Oklahoma City first.
And the Thunder's Russell Westbrook presents an entirely different challenge for Sessions and the Lakers.
Westbrook may be just as quick as the fleet-footed Parker and he's bigger, stronger and more explosive to boot.
The crossover move that Parker embarrassed Sessions with would have ended in a dunk for Westbrook.
In the Lakers' most recent game against the Thunder, Sessions scored seven points, dished out three assists and pulled down five rebounds.
Westbrook scored 36 points, six assists and one rebound in that same contest, and if you were a Lakers fan looking for a little optimism, Sessions did at least win the rebounding battle.
Sessions was not quick enough to stay in front of Westbrook on the perimeter and he wasn't strong enough to deal with him in the paint.
It would be a familiar refrain for the Lakers when it comes to their point guard play, but former Laker Fisher was strong enough to deter most opposing guards from posting him up in the paint. Fisher, however, couldn't score on a consistent basis like Sessions.
Sessions does not have the same quickness as Parker or Westbrook, but he does have the ability to get to the rim with his dribble and knows how to finish when he gets there.
Sessions is also much better at getting his teammates involved in the offense than Fisher ever was, and under his hand, head coach Mike Brown's dribble-drive offense finally seems to make sense.
But is Sessions' offense good enough to override his Derek Fisher-like defense and lead the Lakers to postseason glory?
The Lakers proved in their championship seasons of 2009 and 2010 that superior point guard play was not necessary to win a ring, and even though Sessions is a definite upgrade over Fisher, he might not be able replace Fisher's clutch shooting.
Fisher's big shots when the games mattered the most garnered him a legion of fans who will adorn him with eternal appreciation, but so far the only big shot I have ever seen Sessions make was a three-pointer in a recent overtime win against Dallas in the regular season.
Sessions' ability to score points and put his teammates in the best position to succeed may eventually outweigh his liabilities on the defensive end, but performances like the ones Sessions offered against Parker and Westbrook is not a good place to start.