PER Diem: April 27, 2009

Three games, three fantastic finishes and three underdogs who have given themselves a surprisingly good chance at pulling first-round upsets. Sunday wasn't such a shabby day for hoops, as it turns out, with the added bonus that the double-OT Celtics-Bulls game spared us from having to watch much of the Cavs-Pistons beatdown.

What Sunday taught us more than anything else, though, was how important late-game strategy can be, especially when we get into playoff series in which the teams are more evenly matched. In all three games, there were crucial moments at which strategy made all the difference.

Let's start with a common theme around these parts: If you're up by three points, and the other team has the ball with no timeouts and fewer than 10 seconds left, for goodness' sake, FOUL! I remain shocked at how many teams won't do this, and at how many unnecessary game-tying 3-pointers we've had to witness as a result.

(Such a decision provided the entire backdrop for these playoffs. The Hornets failed to do it in the season finale against the Spurs and allowed Michael Finley to tie the game. If they had simply fouled, we would have three entirely different pairings in the West, with Blazers-Hornets, Nuggets-Mavs and Rockets-Spurs.)

Amazingly, the Bulls and Celtics each managed to mangle this situation Sunday. Boston's violation was particularly egregious, as the Bulls inbounded the ball inside the 3-point line before passing it back out for Ben Gordon's game-tying 3-pointer in the first overtime. With the ball near the free-throw line, there was no risk whatsoever of fouling a 3-point shooter, no way to spin a story about what might have happened. Boston was one arm chop away from a 3-1 series lead.

What made it more puzzling was that the offender was 33-year-old veteran Ray Allen, who stood there placidly while John Salmons stood holding the ball with his back to the basket before firing a pass to Gordon.

(Side note: Doc Rivers gave yet another seminar in Media Savvy 101 after the game. I was trying to figure out how he'd address the non-foul without either (A) throwing Allen under the bus, or (B) making it seem like he forgot to tell the team. Doc's quote: "We always foul, but even when you screw it up, they've still got to hit the shot." Genius. And we still don't know if "you" means Doc or Allen was the one who screwed it up.)

In the second overtime, it was Chicago's turn. As the clock ticked down from 16 seconds the Bulls allowed Rajon Rondo to dribble unmolested up the court, rather than fouling the 64 percent free-throw shooter and eliminating the possibility of a game-tying 3.

I take it this happened because Vinny Del Negro didn't trust rookie Derrick Rose to pull it off without screwing it up and fouling Rondo in the act of shooting, which is exactly what happened to little-used Linton Johnson two games earlier. His postgame comments reinforced that point.

"People think it's easy to foul sometimes," Del Negro said. "But all of a sudden you foul and they are in the act of shooting. Pierce was in that situation and we gave him three free throws earlier in the series."

Of course, Rose didn't need to be on the court for that play, something we'll discuss in a minute.

In the meantime, let's get back to the 3s, because we had two other games in which a team was down by three points in the final seconds.

In the Rockets-Blazers game, it appeared to be an I-know-that-you-know-that-I-know-that-you-know situation. Blazers coach Nate McMillan seemed to think Rockets coach Rick Adelman would foul, and thus designed an inbounds play to get him a catch-and-shoot 3-point look right away.

He got it, too, for Travis Outlaw, but the shot went awry. About the only thing you could fault here is why it was Outlaw and not Brandon Roy or Rudy Fernandez who got the look. Outlaw has hit plenty of huge shots for the Blazers from that spot on the floor over the past two years, but he's had a rough series that got rougher after his miss.

Finally, there was the conclusion of Orlando-Philadelphia, the latest installment of a series that has turned into the "Bizarro" episode from "Seinfeld." Orlando was the league's most prolific 3-point shooting team this season and the Sixers were the worst. Yet -- as Stan Van Gundy lamented during a first-half TV interview -- suddenly Philly can't miss from outside and Orlando can't make one. For the series Orlando is 25-for-81 on 3s (30.9 percent), and Philly is 24-for-57 (42.1 percent).

The entire upside-down nature of the series was summed up best by a three-possession sequence in third quarter in which Orlando's J.J. Redick missed two wide-open 3-pointers and then finally scored by going coast-to-coast and zigzagging past three defenders for a layup. If you're keeping track, this happened a few minutes after 31 percent career 3-point shooter Willie Green knocked down his third bomb in three tries, and just moments before career 34 percent marksman Thaddeus Young hit his third triple to improve to 5-of-7 on the series.

But I digress. When the Magic finally knocked down a 3 -- an off-the-dribble bomb by Hedo Turkoglu to break open a tie game with 1.1 seconds left -- the Sixers had one last gasp, running an inbounds play off a timeout. TV analyst P.J. Carlesimo said the Magic should take a foul, but actually when the clock is this low the strategy reverts back to playing good, solid defense. There's time only for a player to shoot off the catch, so any foul is all but certain to result in three free throws for the opponent. Orlando wisely played it straight, the Sixers finally missed a 3 and the Magic walked out with the win and a 2-2 series tie.

OK …

That covers one important strategic situation. Now let's talk about the other: substitutions. Late-game timeouts present coaches with unique opportunities to substitute offense for defense, or vice versa, knowing that the players they insert won't be needed for a possession at the other end.

The way to do this correctly was illustrated by Adelman, whose Rockets had a two-point lead with 23 seconds left against Portland and still had two timeouts in his pocket. Knowing darn well that he'd use one of them if the Blazers scored, he took Yao Ming and Carl Landry out of the game and put in Aaron Brooks and Chuck Hayes.

Subbing Brooks in was obvious, because the Blazers had four guards on the court; subbing Hayes was the genius part. The little-used sub hardly plays because of his inability to score, but is undeniably the Rockets' best interior defender now that Dikembe Mutombo is out. Hayes stepped up and took a charge on Brandon Roy, Adelman called timeout and got him out of the game before the Blazers could foul him and the Rockets were one win away from the second-round promised land.

In fact, Adelman made the same Hayes-for-Yao, back-and-forth, offense-defense substitution three times in the final nine seconds, continually optimizing the units he had on the floor for the particular situation.

The incorrect way to do it, on the other hand, was illustrated by the Celtics and Bulls … again and again and again and again.

I'm sorry to point this out since it was such a thrilling game -- especially since Doc obviously has had better moments coaching, and Vinny probably will in the future -- but go back and watch a tape of this thing. It's like watching a chess match between Jessica Simpson and Pauly Shore.

You don't believe me? Check out these situations:

With 1:06 left and the game tied at 91, Boston's Ray Allen is shooting a free throw, while Del Negro stands poised to call timeout afterward (we can presume this because he ended up calling timeout seven seconds later when the Bulls finally got the ball).

In other words, the only play that could possibly happen between the free throw and the timeout is a defensive rebound situation. But instead of subbing in Brad Miller or Tyrus Thomas, Del Negro left John Salmons as the "big man" on the block. Rajon Rondo went around him to grab the offensive rebound, and only a tripping foul seconds later on Kendrick Perkins averted disaster.

Amazingly, this happened again. With 18 seconds left in overtime, Boston up by two and Paul Pierce at the line, Del Negro again left his best rebounders on the bench right before a timeout. This time, however, his team grabbed the carom

With a three-point lead and 16 seconds remaining in regulation, Del Negro came out of a timeout with his key defender, Kirk Hinrich, on Paul Pierce, even though Boston's best shooter, Ray Allen, was the main threat in that situation. With a two-point deficit and 39 seconds remaining in the first overtime, he had Hinrich on Allen and Salmons on Pierce, despite the high likelihood of an isolation play for Pierce. Thus his best defender was out of the play on two of the biggest possessions of the game.

At least Hinrich was on the court, which is more than can be said for Lindsey Hunter. At every key moment, Del Negro left his worst perimeter defender, Rose, on the court, while the veteran Hunter -- who is in the league only for his defense -- stayed on the bench. Hunter played one possession at the end of the first half, and that was it.

Even in situations such as the two referenced above, in which the only outcome was a defensive possession followed by a timeout or a foul, Del Negro didn't put Hunter in; instead, we got to see Rose get hung up on a screen for the 183rd time in four games as Allen knocked in a game-tying 3 to send it to overtime. And of course, on that final play in the second overtime, Hunter could have been brought in to pressure the ball and give a foul.

If you think Doc gets off easy here, guess again. On a positive note, he did manage to ace the "put your best rebounders in the game on an opponent free throw before a timeout" test (for instance, he put Brian Scalabrine in for Eddie House with 16 seconds left in regulation and Tyrus Thomas shooting a free throw, and then put House back in for Scalabrine after the timeout. Take note, Vinny. It's not that hard.)

But he's going to be kicking himself for his choice with 39 seconds left in the first overtime. With Boston up by two and having the ball, and Del Negro undoubtedly calling timeout afterward if Boston were to score, he somehow decided to leave the offensively challenged Scalabrine on the court rather than summoning House, Boston's third-leading scorer on a per-minute basis this year. Of course, Scalabrine committed a clear-path foul after Pierce had the ball stolen and fouled out of the game.

Rivers did the same thing with 52 seconds left in regulation and the Celtics down by two, though this is easier to excuse because of the need to rebound a potential missed free throw (Derrick Rose was at the line and Rivers didn't call timeout after the shots).

Of course, then there's the big-picture lineup decision he made: putting in Scalabrine to start the first overtime instead of House, or Marbury, or Tony Allen, or Mikki Moore, or, well, anybody. He'd played six minutes in the preceding two months, and hadn't exactly been enjoying a distinguished career before that point.

And obviously, we still don't know how or why the Celtics failed to foul at the end of the first overtime.

So while all three games were exciting, the tacticians in the audience saw three very different types of battles. Between the lineups and the timeouts, we had the basketball equivalent of a kindergarten class (Boston-Chicago) followed by a grad school seminar (Adelman vs. the Blazers) with the Bizarro series in between just to shake us up a little. At the end of it, perhaps it's not so surprising that Adelman's team is the one that's a game away from advancing.

John Hollinger writes for ESPN Insider. To e-mail him, click here.