How is GSW's Fate Being Decided in the Third Quarter?
For the first 28 games of 2017-18, GSW is 13-7 when ahead at halftime and 7-2 when behind. These are essentially the same percentages (GSW has been 2-0 when tied at half.) In line with this, at the half GSW has been up by 2.9 points in games they won and down0.1 point in games they lost – a modest 3 point difference. Thus, the difference in whether GSW wins or loses appears to occur mainly in the second half.
When I looked at the third- and fourth-quarter numbers, the third quarter stood out as the quarter that made the difference as the fourth quarter on average merely tended to widen the margin be it a win or loss. Wait you say, GSW has lost the third quarter in 5 of its 6 losses (-3, -5, -6, -6, -12) and won it in 18 of its 22 wins (-3, -4, -4, -8), so it is losing record is only 4-5 when losing the third quarter. This part may seem weak, but the third quarter losses are better correlated with games losses than losing the first or second quarters. Moreover remember, GSW lost the third quarter of 5 of its 6 losses, and GSW was 18-1 when it won the third quarter.
This import of the third quarter is already known to close GSW fans that have watched games appear to be decided in the third quarter. However, my question was more detailed, "What happens differently in the third quarters of wins and losses that results in the different resulting point totals?"
As a first cut, I looked at per game averages. Several stats while slightly favorable or unfavorable did not appear to be important to the differences in outcome. These included steals, blocks, and percentage of made shots assisted. During third quarters, GSW had a plus-minus of +10 in wins and -4.7 losses, a difference of 14.7. Considering the difference between wins and losses at the half has averaged 3.0 points and at the end of games, 23.3 points only emphasizes the importance of points in the third quarter. Of the -14.7 difference within the third quarter for losses, -10.1 points derives from GSW scoring fewer points and 4.6 from opponents’ scoring more on average.
What goes into GSW scoring -10.1 fewer points during the third quarter? Only a half point less has come from free throws though GSW has shot one fewer free throw. Though GSW 3-pointers poorly during the third quarter of losses, the difference in points from 2-points shots has been greater than from 3-pointers. For 2-point shots, 3 fewer shots were taken during the quarter (11 to 14 2PA) and with 53.6% 2P% in losses versus a higher 63.7% in wins this meant 3 fewer made 2-pointers (5.9 to 8.9 2PM)and -6 fewer points. For threes, GSW took only -0.6 3PA less (7.7 to 8.3) but shot -11.4% worse (37.0% to 48.4%) with the result being scoring -3.6 points less (8.4 To 12 points). Concerning the point differences, taking fewer shots was more important for 2-point shots and shooting a lower percentage was more important for 3-point shots. Altogether, GSW’s -10.1 fewer third-quarter points were -6 from 2PM, -3.6 from 3PM, and -0.5 from FTM.
Note: While these averages are insightful, they do gloss over that GSW’s third quarters in its 3 road losses have been worse (-10.3 points) than its 3 home losses (-4.3).
While one can argue that the dominating difference in third-quarter outcomes was GSW scoring less, its opponents did score 4.6 third-quarter points more in GSW losses than GSW wins. Of these +4.6 more third-quarter opponents points in GSW losses, opponents made +1.7 points from free throws (GSW committed 1.1 more PF), +0.4 points from 2-pointers (6.8 to 6.6 2PM), and +2.4 points from 3-pointers (6.6 to 5.8 3PM). The biggest contribution, from 3PM, derived manly from better 3P%, 38.3% compared to 29.8%, though opponents took a half more 3PA.
CONCLUSION
GSW’s losses have commonly centered on their own scoring performance in the third quarter where they have on average scored 34.3 points in wins and 24.2 points in losses. While opponents have scored more in the third quarter of GSW losses 28.8 points to 24.3 in GSW wins, this has mainly come from GSW committing 1.1 more foul (1.7 points) and opponents shootings a substantially higher 3P% (2.4 points) in third quarters of GSW losses than in GSW wins.