Diamondbacks Playoff Odds: Weekly Update

Seven days has passed since the last time we looked at these, so seems an appropriate point to see how things have changed since then. Arizona has gone 3-3, while San Francisco has played an extra game, but lost it, so went 3-4 on the week. This extended the Diamondbacks' lead in the division by half a point, to its current 2.5 game level. However, more importantly, a week came off the schedule, without the Giants making any inroads at all, which makes their task the rest of the way, that much tougher.

We'll look at the same three scenarios as last time, for the Diamondbacks win percentage the rest of the way, and break down what that means the Giants need to do to overtake us.

Scenario 1: Diamondbacks maintain current Win % (.552).

At that pace, we would go 89-73. To finish with 90 wins, the Giants would need to go 23-13 the rest of the way. That's a .639 W% - 11 points up on this time last week, close to the .650 the Phillies have managed in the NL over 2911 In terms of current form, the Giants have won 23 games in their last 48 contests, going 23-25, so they now have a dozen less than that to play with.

Next, assume that the D-backs play .552 baseball over the 31 games against non-Giants. That would give us 17 additional wins, putting us on 86 wins before playing SF. The list below shows what the Giants would need to do in their 30 non-Dbacks games to beat us, based on the result of their games against us.

• If we go 6-0 (92 wins), SF has to go 26-4
• If we go 5-1 (91 wins), SF has to go 24-6
• If we go 4-2 (90 wins), SF has to go 22-8
• If we go 3-3 (89 wins), SF has to go 20-10
• If we go 2-4 (88 wins), SF has to go 18-12
• If we go 1-5 (87 wins), SF has to go 16-14
• If we go 0-6 (86 wins), SF has to go 14-16

The Giants current W% of .532 is 16-14 over 30 games. As last week, if they did that in the match-ups against other teams, we could lose both series, go 2-4, and still win the West. That hasn't changed. But what has, is the path the Giants have if we do any better - it has become a lot steeper. If we split the six games, last week, the Giants needed to go 23-14 elsewhere to beat us, a .622 W%. After an anemic 3-4 record, that number is now 20-10, a 667 W%.

Scenario 2: Diamondbacks maintain current Pythagorean W% (.513).
We may have split our six games, but we were outscored 19-26, so our Pythagorean - the win percentage based on runs scored and allowed - takes a hit, and we are now over-performing it by five games. The Giants, despite losing an extra game, were only outscored by one run overall, 20-21. Let's assume that Arizona drops back to .513 over the next 37 games. That would be 19 wins, giving them 88, the same as last week. To reach 89, the Giants now need to go 22-14. That's a .611 W%, up 30 points on last week, and way ahead of their current .532 real W%, .

Repeating the exercise described above for the Giants series, what do we find? .513 over 31 non-Giants games is a 16-15 record, putting Arizona at 85 wins, plus the games against San Francisco

• If we go 6-0 (91 wins), SF has to go 25-5
• If we go 5-1 (90 wins), SF has to go 23-7
• If we go 4-2 (89 wins), SF has to go 21-9
• If we go 3-3 (88 wins), SF has to go 19-11
• If we go 2-4 (87 wins), SF has to go 17-13
• If we go 1-5 (86 wins), SF has to go 15-15
• If we go 0-6 (85 wins), SF has to go 13-17

As last week, that's one less win than Scenario #1, but doesn't really help the Giants cause. They still really need to beat the Diamondbacks head-to-head. Even a split would leave them with a mountain to climb in their other 30 games.

Scenario 3: Diamondbacks play .500 ball.
As a final estimate, let's say Arizona simply plays even down the stretch, splitting the remaining 37 games. That's 18.5 wins, taking them to 87.5. To reach 88, the Giants still need to go 21-15, which works out at a .583 W%, twenty-five points higher than the .558 when we checked last Saturday. Crunching the numbers as before, for the head-to-head games: 15.5 wins in the 31 non-Giants encounters = 84.5 wins, so:

• If we go 6-0 (90.5 wins), SF has to go 24-6
• If we go 5-1 (89.5 wins), SF has to go 22-8
• If we go 4-2 (88.5 wins), SF has to go 20-10
• If we go 3-3 (87.5 wins), SF has to go 18-12
• If we go 2-4 (86.5 wins), SF has to go 16-14
• If we go 1-5 (85.5 wins), SF has to go 14-26
• If we go 0-6 (84.5 wins), SF has to go 12-18

As we went 3-3, this is the scenario which unfolded over the past week, but San Francisco going 3-4 has, as in the other two hypotheses, hurt them. A split of their contest with us, last week, required a .568 W% in SF's other games. Now, the equivalent number is at .600.

Conclusion
Despite the past three games, it has been a good week for the Diamondbacks, increasing their lead and taking seven games off the schedule for the Giants. That doesn't even take into account the opponents: as previously noted, tomorrow is likely the last time, outside of the contests against San Francisco, that Arizona will see a team above .500. So if we can get through the weekend with the lead at more than two, it'll be like clearing Becher's Brook in the final lap of the Grand National.

CoolStandings.com has us at a 68.0% chance of taking the division, up 5.8% on last week. Even Baseball Prospectus has cut five percent off the Giants' odds, though they still sit at 69.4%. I've got a bottle of champagne in the fridge for when they finally put the Diamondbacks above 50% - I'm thinking that will likely be around game three of the World Series...