There's never a shortage of storylines when the Boston Celtics and Los Angeles Lakers do battle. But that's especially true Sunday, as the two meet for the first time this season -- and the first time since last year's NBA Finals.
Here are just three factors that make Sunday's one of the most anticipated games of the regular season.
1. Shaq's wearing green in LA: Shaquille O'Neal knows all about this rivalry. Back in his LA days, O'Neal faced the Celtics 10 times, averaging 29.9 points per game and 15.1 rebounds. He shot an incredible 67.1 percent from the field in those games, as the Celtics countered with the likes of Mark Blount, Tony Battie, Vitaly Potapenko and even Dino Radja. In those years, Shaq averaged more only against the Nets and the Magic, his former team.
Shaq's dominance of Boston reached a new level on March 21, 2003. The Celtics tried to use their centers to front O'Neal, and the results were disastrous. Shaq went off for 48 points on 19-for-24 shooting, also adding 20 rebounds for good measure. Bill Russell had a front-row seat for what was arguably Shaq's second-best individual game (tough to beat his 61-point, 23-rebound game against the Clippers in 2000).
If he suits up Sunday, no one expects O'Neal to experience a one-game renaissance. He's seven years removed from his previous Celtics-Lakers game, not to mention five weeks from his 39th birthday.
But this weekend, O'Neal will taste the rivalry from the other side for the first time. He'll have to answer to Lakers fans now questioning whether his Celtics stint should preclude his number from being retired.
By no means is Shaq the first to see the rivalry from both perspectives, but the list of key players to do so is rather short.
Hall of Famer Clyde Lovellette won a title with the Lakers as a rookie. Nine years later, he came to Boston where he finished his career with a pair of championships, including one against the Lakers. Lovellette is the only player with a title as a member of both teams. But his Lakers ring came when the franchise was in Minneapolis, before the Celtics and Lakers had ever squared off in the NBA Finals.
How about Bob McAdoo? He spent 20 games with the Celtics in 1979 and later spent four seasons coming off the bench for the Lakers. Along with Lovellette, he's the only other Hall of Famer to play for both teams. But in truth, McAdoo was seemingly unwanted during his brief tenure in Boston. He's perhaps best remembered for bringing in the draft picks ultimately dealt for Robert Parish and Kevin McHale.
Gary Payton will almost certainly make it three Hall of Famers. Though he spent only one season with each team, both after turning 35.
Like Lovellette, Don Nelson and Mel Counts played in the NBA Finals for both franchises. In fact, Nelson lost to the Celtics in the 1965 Finals as a part-time player for the Lakers. The following offseason, he signed with the Celtics and was a key contributor to the team that beat the Lakers in the 1966 Finals.
Shaq isn't the first player to taste the Celtics-Lakers rivalry from both sides, but he'll go down as the greatest to do so.
2. The road to home-court advantage: Think this is just another game in January? Don't underestimate the significance of Sunday's matchup for home-court advantage in the playoffs.
It's no sure thing that these two teams would meet in the Finals. With the best record in the NBA, the Spurs certainly will have their say down the line. Either way, it's these early head-to-head matchups that often determine who hosts Game 1.
Boston needs no reminder what that means. The last four champions had home-court advantage in the NBA Finals.
The Celtics and Lakers have squared off 12 times in the NBA Finals. The team with the better regular-season record has won 10 of those.
So what do the schedules tell us about who will end up with the NBA's best record?
Heading into this West Coast road trip, the Celtics have played the third-easiest schedule in the NBA. Of their 44 games, 25 were against sub-.500 teams. Boston is 20-5 in those games. The Spurs, who have made it through the season using only one starting lineup, are 22-1.
While the Celtics have certainly had it easy until now, no one has coasted as much as the Lakers.
As of Thursday, the Lakers had played the easiest schedule in the NBA, with opponents combining for a .453 winning percentage. L.A. is just 8-6 against teams .500 or better, while the Celtics are 14-5.
That's all about to stop for the Lakers, who have the second-toughest remaining schedule in the NBA. Only the Sacramento Kings have a more difficult road ahead.
Boston will also have a more challenging second half, but still just the 19th toughest in the league.
With the Celtics' roster finally getting healthy and the Lakers' challenging schedule, a win Sunday could help ensure that the TD Garden hosts any potential Game 1 in this rivalry.
3. How old is too old? Jerry West made headlines in Los Angeles last week by saying the Lakers were "getting long in the tooth" -- blaming their age for a lack of defensive consistency.
"If there's a loose ball now, how often do they get to it? The reason you can't play defense is because you can't," West said to a group of Orange Country car dealers.
Ten players on the roster are in their 30s, including four starters and the sixth man. The Lakers are indeed old.
But if the Lakers are getting long in the tooth, the Celtics must be losing their teeth.
After all, Shaquille O'Neal, the NBA's oldest player, is about to turn 39.
Ray Allen, 35, leads the team in minutes despite being one of the 20 oldest players in the game. He's the second-oldest player to have started every game this season. Throw in Paul Pierce (33) and Kevin Garnett (34), and the Celtics are relying on a core of aging stars.
Yet, the Celtics are just the fifth-oldest team in the NBA. Hard to believe, isn't it?
According to the Elias Sports Bureau, the Celtics' average age is 28.6. The Miami Heat (30.4) are the oldest, followed by the Lakers, Mavericks and Nuggets.
Keep in mind, that number includes everyone on the roster. In Boston's case, that means Avery Bradley, who at 20 is the NBA's third-youngest player. But Bradley has played only 66 minutes all season and currently suits up for the Maine Red Claws of the NBA Development League. At 23, Luke Harangody is the team's second-youngest player, but he too has seen little action.
Clearly, the Celtics are the older team where it counts.
In fact, the average age in the Celtics' starting lineup this season is 32.5. According to the Elias Sports Bureau, that's the oldest in the NBA this season. Even with Rajon Rondo somehow still only 24 years old, the Celtics have consistently been tipping off with the oldest starters in the league.
While West cited regressing defense as a product of age, perhaps a bigger concern should be the general rigors of an NBA season. Just how old did Ray Allen's legs feel in last year's Game 7? It was his 104th game of the season.
For some perspective, consider that the 1997 Chicago Bulls had the oldest starting lineup to win an NBA championship. On Game 1 of the Finals, Chicago's starters averaged 32.8 years, according to Elias.
The Celtics' usual starting four with O'Neal at center would be the oldest ever to win a title.
However, with Kendrick Perkins expected to regain his starting spot, the Celtics' starting lineup will get nearly 13 years younger.
The Lakers spent much of the week addressing West's comments about age. As long as they face the Celtics, age goes out the window.
In the end, all this talk of age likely ignores the true concern: minutes.
Among active players, only Jason Kidd has logged more career minutes than O'Neal, Garnett and Allen. Pierce is ninth on that list.
Jeremy Lundblad is a researcher with ESPN Stats & Information. He provides statistical analysis for ESPNBoston.com.