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Phoenix Wins With Defense (!!), Ball Movement, and a Dose of Taurasi

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For the first time this season, the Phoenix Mercury made their "rover" defense look brilliant.

That's right, Phoenix won with defense.

Diana Taurasi’s outstanding 4th quarter performance and clutch defense has gotten all the headlines for the win thus far. However, it was the huge increase in defensive intensity and offensive focus in the second half that led to the Mercury’s 99-94 comeback win over the Comets.

Of course you could argue that Taurasi was singularly responsible for the momentum shift throughout the entire second half.

Down by 8 at halftime, the Mercury picked up the defensive intensity led by Taurasi, who picked up Shannon Johnson almost at half-court for most of the 3rd quarter.

On offense, Phoenix’s defensive intensity created a better rhythm on offense and allowed them to score more easily in transition, which got the momentum back. Taurasi’s shooting and playmaking ability figured prominently in that change as well.

But the thing that struck me most about this game was ball movement – on both sides of the ball. And really, it was a tale of two halves. Houston’s ball movement got them the lead in the first half and Phoenix’s ability to disrupt Houston’s ball movement and establish their own is what led them to the win.

And there was an interesting statistic displayed during the web cast that I think supports the ball movement story of this game very well – assists to field goals made ratio.

Stopping Houston’s ball movement

In the first half, Houston was moving the ball extremely well and getting almost whatever shot they wanted against Phoenix’s rover defense, from three pointers to baseline drives to second chance points in the paint.

I don’t know exactly what Mercury coach Corey Gaines said at halftime, but Phoenix came out with a renewed sense of purpose and upped the intensity. Gaines did let us in on the following in the post game press conference:
"It’s tough because every team you play has a different offense that they throw at you and we’re still working on our rover defense. As soon as Julie (Hairgrove), my defensive coach, figures out what they’re doing, we try to make adjustments to their style of play."
With Taurasi picking up the point guards near mid-court, Phoenix was able to completely disrupt the flow of Houston’s offense. And it wasn’t just Taurasi’s defense, but the entire team rotating faster, getting their hands in the faces of Houston’s shooters and deflecting passes. It's what the rover defense has been missing all season, or at least in every game I've seen.

Even when they fouled the Comets' ball handlers, the message was clear – the Comets weren’t going to get any more easy baskets against the zone.

Increasing their own ball movement

On offense, when Phoenix wasn’t running and scoring in transition, they were swinging the ball and putting more pressure on the Comets’ defense by forcing them to rotate. Taurasi was huge on offense as well, not only with her scoring, but by using her superior court vision and ball handling skills to find open teammates for scoring opportunities.

By playing so effective in transition and forcing the Comets to really work on defense, by the middle of the 4th quarter, it was clear that Houston just ran out of gas.

Assist to field goals made ratio

It’s difficult to capture the effect of shifting momentum with a statistic, but in this case the change in assist to field goals ratio (ast/fg) did actually represent the drastic shifts in ball movement throughout the game.

I think of ast/fg as an approximation of assisted scoring opportunities. In other words, it tells us how often the team’s made field goals came as the result of a pass from a teammate. In this game at least, the team with the higher ratio was definitely moving the ball more effectively.

For the game, the Comets had a big advantage in ast/fg, because of their excellent ball movement in the first half. At halftime, the Comets had 17 asts to 22 fgs (77%) while the Mercury had 8 asts on 17 fgs (47%). This mirrors what I observed in the first half – for the most part, the Mercury were scoring on individual plays, whereas the Comets were scoring by moving the ball within their offense.

In the second half these numbers shifted slightly. The Comets had 10 asts on 14 fgs (71%) and the Mercury had 11 asts on 15 fgs (73%). Although the Comets percentage of assists didn’t change drastically, you’ll notice the number of assists did. Meanwhile the Mercury increased their number of assists while also shooting more efficiently from the three point line (45%). They were moving the ball around and finding higher quality scoring opportunities.

When you look at the whole picture, the Mercury’s considerable increase in ball movement and efficiency on offense got them back into this game. But Diana Taurasi’s ability to create for herself won it.

The MVP candidate puts the Mercury over the top

12-year WNBA veteran Tina Thompson is having a great season. Taurasi is just having a better season.

Currently, ranked in the top 5 in’s MVP rankings, Taurasi put on a show today that perfectly illustrates why she stands to be a perennial MVP contender for the rest of her career.

On an afternoon in which she scored her 3000th point, she complemented her scoring with 6 assists, 5 rebounds, 3 blocks (!!) and 3 steals, not to mention going 7 for 7 from the free throw line. That’s right, she did absolutely everything a player can be expected to do.

So when she turned it up a notch in the fourth quarter along with the improved team defense and ball movement, it was just too much for Houston to respond to. The Mercury outscored Houston by 11 points in the 4th.

You might look at Taurasi’s team-high 19 shots and say that she was shooting too much to be helping her team. But when you shoot as efficiently as Taurasi did, you actually draw the attention of the defense and open up the offense for your team.

Taurasi’s field goal percentage was 47%, but if you consider the value of the three pointers she made in addition to her perfect outing at the free throw line, you get an even more spectacular story. I’ll borrow the Scoring field goal percentage (ScFG) statistic from Bob Chaiken for this one.
Bob Chaikin, whose fine statistical research can be found at, ranks shooting efficiency with a statistic called scoring field goal percentage. The formula is: (Two point field goals made + 1.5 X Three point field goals made + Free throws made/2) / (Field goals attempted + Free throws attempted/2).

This method provides a more complete picture than field goal percentage does because it accounts for the added value of three-pointers made plus the points produced by drawing fouls and making free throws.
Taurasi’s ScFG% for the Comets game was 67%. That’s astounding. The NBA league average usually hovers around 52-53% to give you a sense of how good that is (I haven’t calculated the WNBA’s average, but will eventually). That’s what MVPs do – carry the team in whatever way necessary to win games.

The Big Picture

When you’re moving the ball, have five players in double figures, have two players able to drive and get to the free throw line (Pondexter was 8-10), and have your defense working, you’re tough to beat. Having an MVP candidate on top of all that makes winning games much easier.

In fact, there’s a pretty reliable formula for Mercury wins this season – when the Mercury are able to keep the ast/fg differential within a few percentage points (meaning disruptive defense and ball movement on offense) and Taurasi scores above her average of 23.9 points per game, the Mercury win. The one exception so far just glancing through box scores, is the Seattle game in which Taurasi had 37 points in a loss.

I haven’t looked at these numbers across the league, but it would make sense that ball movement and star power have a major effect on the outcome of games across the WNBA.

Related Links:

Mercury, Taurasi knock off Comets

ESPN shot charts (I love these things)

Transition points:

Just for a point of reference, the Mercury began the season 2-6. During those losses, their ast/fg ratio was at 47%, the same as it was during the first half of the Comets game.