Injuries. Dead legs. Grueling schedules. Welcome to January in the NBA. It’s Fan-tastic!

Sure, we have our occasional marquee matchups, such as last night’s twin bill of Spurs-Pistons and Kobe-Le-Bron, er, Lakers-Cavs. But the previous night offered a more typical sampling of NBA fare at this time of year.

For instance, I spent Wednesday night watching the Rockets and Kings do battle. I’m not saying this was the worst game I’ve ever seen (I’ve witnessed some brutally bad college games), but let’s just say it would definitely be part of the discussion. For starters, this game was more notable for who wasn’t playing than who was. Houston’s Yao Ming was out following toe surgery, and will be on the sidelines for three more weeks. Tracy McGrady’s bad back flared up, so he sat too. On the Sacramento side, Peja Stojakovic bowed out early in the second half with back trouble of his own, having groaned his way to just three points in 28 minutes. That took care of our three All-Stars. But to further lower the quality of play, Sacramento’s Shareef Abdur-Rahim, Bonzi Wells, and Brian Skinner, and Houston’s Stromile Swift, Derek Anderson, and Jon Barry also sat out.

With so many capable players watching in their biz-casual finest, the game was notable for its sheer lack of athleticism. I’d say the most athletic player on the floor was Sacramento’s Kevin Martin, and if you don’t know who Kevin Martin is, well, that’s kind of my point.

Let me give a brief wrap-up for those of you who missed the game. Actually, “missed the game” is a bit strong. “Dodged the coma-inducing bullet” is more like it. At any rate, the Kings shot 42%, allowed 19 offensive rebounds, gave up uncontested jumpers on nearly every Houston possession … and won by eight.

My point in bringing up this game is not to commiserate over what I had to sit through (although I must say it’s quite cathartic). Rather, it’s a pointed example of what basketball at this time of year entails, and how successful teams can navigate around it. Because while Sacramento and Houston may be two of the league’s more dire examples, nearly everybody is at less than full strength at this point. Combine the attrition of injuries with energy-sapping road trips, and it’s a rare team that can survive the last few legs of a road trip or the dreaded “four games in five nights” that the schedule-makers often foist upon them.

The first and most important lesson is that depth matters. In November and early December, you can get by with a thin bench because your starters generally are healthy. That’s how the Clippers raced out to such a good start. But by this time of year, guys are dragging. Even the ones in the lineup every night are usually nursing one minor tweak or another, such as the back problem that has hampered Stojakovic most of the past month. And, surprise surprise, that Clipper team that looked so good two months ago hit a wall once two of their wing players got hurt.

On the other hand, a friendly schedule and a run of good health can help a team survive these pitfalls. It’s no accident that the Knicks chose now to have a five-game winning streak. Yes, they’re a little more comfortable with Larry Brown’s system, but they’re also entirely healthy for the first time all season while many of their opponents are practically bed-ridden. Throw in a friendly schedule that gave them 10 straight nights in their own beds, and it’s clear the Knicks were set up to succeed. Next week, with five games in seven nights, it might not be so pretty.

But the Knicks have another advantage helping them this time of year. Even if somebody gets hurt, they have adequate replacements available. The one “advantage,” if we can call it that, of Isiah Thomas importing so many overpaid, mediocre players is that there’s always a decent backup around. Should Eddy Curry or Quentin Richardson have another stint in the trainer’s room – hardly an unlikely scenario – the Knicks can plug in a Maurice Taylor or a Trevor Ariza and move forward.

Contrast that with the Rockets and Kings, who are paying the price for their woeful second units. With McGrady and Yao out, Houston had to plug in players like Ryan Bowen (14 scoreless minutes) and rookies Luther Head and John Lucas (a combined 5-of-16 with four turnovers). Similarly, the Kings’ frontcourt is so emaciated that at one point they had 6-foot-7-inch Corliss Williamson playing center. Meanwhile, erratic youngsters like Martin and Francisco Garcia played major minutes on the wings, and if Peja’s back doesn’t improve, both are likely to start this weekend.

The second lesson, of course, is that if you don’t have depth, then you at least need durability. Just ask the Pistons – for whatever reason, their starting five seems completely immune to the rigors of an NBA regular season, which makes their poor second unit a much less pressing concern. For a local example, take the Nets – a team similar to the Rockets and Pistons in that they combine a great starting unit with weak bench play. The Nets are 12-5 when Jason Kidd, Richard Jefferson, Vince Carter, and Jason Collins all play at least 18 minutes. But in the games Collins has been limited by knee problems or out entirely, they’re 6-7, and of course they looked very beatable in San Antonio on Tuesday with Jefferson out of action.

So if you find yourself watching a game in the coming weeks that gives off the same aroma that Wednesday’s Kings-Rockets game did, try to have a little sympathy. In many cases, the players are running on fumes and the coaches are forced to use guys who started the year on the inactive list. Blame the league for scheduling too many games in too short a time, or blame our greedy selves for slavishly watching all of them. But know this: The January doldrums are a part of every NBA season. The difference is that some teams are better prepared for it than others.

Mr. Hollinger is the author of the 2005-06 Pro Basketball Forecast. He can be reached at jhollinger@nysun.com.