Just when it looked like the Phoenix Suns would be lucky to play .500 ball, they’ve launched one of the year’s longest winning streaks and have the fifth-best record in the Western Conference. This is not simply good fortune, and their recipe for success includes what could be profound lessons for the coaching staffs in New York and New Jersey.

The outlook was grim for Phoenix when All-Star center Amare Stoudemire underwent microfracture knee surgery just before training camp that would keep him out of the lineup until February. Stoudemire’s averages of 26.6 points, 55.9% shooting, and 8.9 rebounds were the engine driving Phoenix’s high-scoring machine. So it’s something of a surprise that when the Knicks visit America West Arena tomorrow night, the home team will be the league’s hottest squad; entering last night’s game at Golden State, the Suns had won seven in a row, and their 11-5 record was far better than anyone outside of Arizona expected at this point.

The fact that Phoenix is winning is a surprise, but the real stunner is how they’re doing it.

Last year’s Suns won with a small frontline. Stoudemire is 6-foot-10, 245 pounds, about normal size for a power forward – except he played center. Instead, the Suns played 6-foot-7-inch, 228-pound Shawn Marion at power forward, routinely giving up several inches and dozens of pounds in the matchup. With a lineup filled out by swingmen Joe Johnson and Quentin Richardson and quarterbacked by MVP Steve Nash, the Suns won 62 games by running past their opponents and scoring in bunches. The Phoenix Principle was to play your best five athletes and force your opponent to adjust to your game.

The plan made coach Mike D’Antoni look like a genius and secured him Coach of the Year honors. But the team retreated somewhat from its uptempo style and small lineup during the Western Conference Finals, often going with reserve pivotman Steven Hunter for long periods in a five-game series loss to the Spurs. The off-season acquisitions of aging Knicks forward Kurt Thomas and amnesty provision refugee Brian Grant to provide more traditional inside play indicated that Phoenix was continuing to back away.

But once the 2005-06 season started, Phoenix went right back to its bread and butter, featuring a small, quick lineup despite the absence of Stoudemire. Boris Diaw, a 6-foot-8-inch swingman who was essentially a throw-in in the off-season deal that sent Johnson to Atlanta, is seeing major minutes in the pivot. And as the Suns’ 130-85 thrashing of the Trail Blazers on Tuesday night attests, they have floored it in the tempo department.

The advantage most small NBA players have over their larger counterparts is quickness, and it’s clear the Suns are again using that advantage on offense. They presently rank seventh in Offensive Efficiency, (points per 100 possessions) at 108.4, and first in tempo at 95.3 possessions per game. A typical Suns possession involves racing down the floor before rotating the ball between two or three players spotting up on the arc while their teammates cut toward the basket. This leaves opponents struggling to keep up and usually results in someone getting a good look from downtown or an easy lay-up.

Defensively, a quick team uses its advantage to press and trap on the perimeter rather than bang in the paint. But that doesn’t mean it’s useless inside – quick teams can usually surprise opponents with sudden double-teams and blocks.

Last year, the Suns used their quickness to post an Offensive Efficiency rating of 114.7 that astonished veteran observers. But their Defensive Efficiency of 107.0 was merely average. This season, the Suns are using their smaller, quicker lineup effectively on both ends of the floor, ranking fourth in the NBA in Defensive Efficiency at 101.2. In addition, they are fifth in blocked shots at 6.6 per game and seventh in rebounding, grabbing 43.4 per game.

This should open the eyes of someone on Larry Brown’s coaching staff as the Knicks prep for Friday night’s game. The Knicks have been bending over backward to find lineups that conform to the standard dictates, even signing Qyntel Woods, a walking argument for an age-limit, in a desperate attempt to find a small forward. With Stephon Marbury and Jamal Crawford, the Knicks’ talent concentration is at guard, and Brown has often used three-guard sets featuring Marbury, Crawford, and Nate Robinson on the floor in crunch time.

In Phoenix, the trio’s range from the perimeter will space the floor better than the Knicks’ conventional sets and open up more driving lanes. A smaller setup would also be a good fit for rookie power forward sensation Channing Frye, who has shown excellent range on medium distance jumpers.

On defense, a smaller lineup would play to the Knicks’ strength of forcing turnovers. The Knicks’ 17.9 takeaways per 100 possessions rank fourth in the league, and a small lineup would require more trapping and double-teams, which often force turnovers.

On the other side of the Hudson, the Nets have also gone small with great success in the past. In last season’s 107-85 win over Detroit, foul trouble and injuries on the already thin front line forced coach Lawrence Frank to go to a five-guard lineup for most of the third quarter. The Nets proceeded to outscore the Pistons 25-11 in the frame and put the game away.

This season, Frank has increasingly gone with three- and sometimes four-perimeter player squads. This capitalizes on the Nets defensive design on the perimeter and forces them into more of an up-tempo game on offense, which is one of point guard Jason Kidd’s biggest strengths. Yet neither local team employs these small lineups for more than a few minutes each game.

Phoenix is winning largely because it has adapted a game plan to its personnel. When Stoudemire returns, the Suns will be that much more of a threat to win the Western Conference and perhaps an NBA title. Meanwhile, both the Knicks and Nets are struggling in part because they are reluctant to abandon conventional lineup structures. It’s a long shot, given Brown’s renowned stubbornness, but hopefully a light will go on when he sees the Suns’ success with their unconventional lineup.

mjohnson@nysun.com