The Cincinnati Reds (87-66) stand one game behind the Pittsburgh Pirates (88-65) with nine to go.

Tonight’s titanic struggle begins one of the most anticipated stretches of the regular season — six games out of nine with the Pirates in what has seemed like a season-long battle for second place in the NL Central Division. The Reds are two games behind the Cardinals for first place.

Explaining the Pirates’ Breakthrough

Depending on how one views Game 163, the Pirates are on the verge of reaching the postseason for the first time since 1992, which is also the last time they put together a winning season. Only the hapless Kansas City Royals have a longer run (27 seasons) of postseason futility. Not surprisingly, the Pirates success in 2013 has generated excitement and a boost in home attendance.

It’s worth asking the question, what factors have caused their sudden revival?

One interesting explanation is a new, aggressive two-pronged strategy of run prevention. Ordered directly by general manager Neal Huntington last fall, the two tactical components are a greater use of defensive alignment shifts and pitchers throwing more two-seamed fastballs.

First, Huntington instructed all the teams in the Pirates’ organization, including the big league club, to begin paying attention to data collected by the Pirates newly strengthened analytics department tracking the location of thousands of balls that have been put in play. The result is that the Pirates are now one of the growing number of teams that markedly shift their defensive alignment based on the hitter. Remember all the times in the Milwaukee series recently when the Reds hit the ball hard back up the middle only to find Scooter Gennett there? That’s this stuff. It’ll be Neil Walker waiting there this weekend and next.

The second part of the Pirates’ run prevention strategy is the ground war — or rather the ground ball war. Huntington ordered Pirates’ pitchers, from A.J. Burnett on down, to learn two-seam fastballs as a way to generate more ground balls. The impact of Huntington’s policy has been profound. The Pirates’ ground ball percentage has jumped from 46.6% to 52.4% in one season. The NL league average is 45.6%. Pirate starters lead baseball in ground-ball rate by five percent. While it’s true that ground balls become hits and errors at higher rates than fly balls, they also generally don’t become doubles, triples or home runs.

[While I’m solidly skeptical of the evidence offered to prove the bottom line claims of this new strategy (for example, the defensive efficiency improvements look less impressive if you use 2009 as the baseline instead of the all-time worst 2010 Pirate team), what’s undeniable from reading those linked articles is the impressive way that the organization has adopted next-generation Moneyball and sabermetric strategies and changed its culture from top-to-bottom, including their old-school manager. It shows the profound difference a general manager can make in how a major league baseball team approaches the game.]

In addition to new-fangled run prevention, Huntington also pulled off some old-timey run addition by trading for good hitters at the deadline. Unlike the Reds, Pittsburgh didn’t choose to do nothing, so there will be new Pirates playing key roles in this series. Huntington acquired left-handed first baseman Justin Morneau from the Twins and outfielder Marlon Byrd from the Mets.

Also, Huntington has apparently insisted that back-up catchers dive into dugouts to make plays.

But whatever the cause of the Pirates newly winning ways, here we are. One game behind with nine to go.

The Pirates’ Offense

An explanation for the Pirates renaissance that can definitely be ruled out is their offense. They rank tied for eleventh in runs scored in the NL (Reds are 2nd) ahead of only the Cubs, Padres and Marlins. Their OBP is 10th in the NL (Reds 3rd).

(Did you know that the LA Dodgers are only 8th in the NL in runs scored over the past 30 days?)

Here is the likely Pirates’ starting lineup.

Player Bats Pos Age BB% OBP ISO wRC+ SB oWAR dWAR
Starling Marte (R) LF 24 4.6  .342 .159 120 36 2.8 1.9
Neil Walker (S) 2B 27 9.0  .333 .137 103 9 2.1 0.8
Andrew McCutchen (R) CF 26 11.1  .408 .196 160 27 7.4 1.0
Justin Morneau (L) 1B 32 10.3  .362 .039 94 0 0.0 0.0
Marlon Byrd (R) RF 35 3.8  .338 .184 131 0 0.4 0.1
Pedro Alvarez (L) 3B 26 7.9  .290 .236 106 2 2.5 0.1
Russell Martin (R) C 30 11.5  .330 .152 103 9 2.7 2.5
Jordy Mercer (R) SS 26 6.1  .328 .130 104 3 1.7 0.4

[Key: BB% = walk-rate – Votto 18%, Heisey 3.9%%; ISO = isolated power – Bruce .225, Leake .063, Izturis .048; wRC+ = weighted runs created, 100=average – Choo 152, Phillips 92, Izturis 27]

Jose Tabata has been playing LF a lot lately, with Starling Marte injured, and Jordy Mercer shares time with Clint Barmes at shortstop. Marte is back, although he missed Thursday’s game to be with his wife who was giving birth. Other than MVP-favorite Andrew McCutchen, what you can say positive about the Pirates’ lineup is balance and depth.

Starting Pitching Match-ups

The Pirates’ starting pitching has been outstanding this season and it’s lined-up well to face the Reds this weekend. Their team ERA for starters is fourth in the NL (Reds are second) and their FIP is second (Reds sixth). Friday and Saturday’s games feature four of the league’s top ten pitchers.

[Key: SwStr% is the percentage of their pitches when the batter swings and misses. Long post explaining ERA, FIP, xFIP and SIERA here. GB% is the percentage of balls in play that are ground balls. The blue and red numbers indicate the pitcher is one of the best 12 (blue) or worst 12 (red) starters in the National League in that category. Minimum innings assumed was 100. Sixty-four pitchers in the NL met that innings criteria.]

Fri 7:05 Age IP K/9 BB/9 SwStr% ERA FIP xFIP SIERA GB%
Mat Latos (R) 25 197.2 8.15 2.76 10.7 3.14 2.97 3.50 3.62 44.8
Francisco Liriano (L) 29 148 9.00 3.59 12.9 2.92 2.86 3.17 3.55 50.6

Francisco Liriano is being mentioned as a candidate for NL Comeback Player of the Year (an award he won in the AL in 2010). He’s among league leaders in strikeout-rate, FIP and xFIP and leads the league in swinging strike percentage. So he misses bats. Liriano has pitched better at PNC Park this year than on the road and he’s been tough on the Reds’ left-handed hitters so far. The Reds have won all three of his starts in 2013, but in two of those games Liriano was the victim of poor run support. Overall, he’s pitched pretty well against the Reds.

Mat Latos is coming off one of his most frustrating starts of the season. Against the Brewers, he gave up five runs, all on bloop singles. He hasn’t pitched all that well in his previous four starts against the Pirates. Twice he only lasted five innings.

Sat 7:05 Age IP K/9 BB/9 SwStr% ERA FIP xFIP SIERA GB%
Homer Bailey (R) 27 198.1 8.76 2.09 10.9 3.40 3.10 3.21 3.26 45.8
A.J. Burnett (R) 36 176 9.77 3.22 10.2 3.43 2.77 2.97 3.15 56.6

A.J. Burnett has the highest K/9 for any starting pitcher in the National League with more than 100 innings pitched. He’s been Homer Bailey’s equal or better by most measures. Burnett has faced the Reds twice this season, neither time throwing all that great.

Let’s see … Homer Bailey pitching in Pittsburgh late in September against A.J. Burnett …

That’s right, as if you need another reason to watch this game instead of college football, Homer will take the mound one week to the day before the anniversary of his first no-hitter at PNC. Burnett, who faced Bailey last Sept. 28, nearly matched the lion slayer that night, giving up only one run in the Reds 1-0 victory.

Bailey has only pitched against Pittsburgh twice this season, a no-decision in June and a loss in July. He threw well in both games, however, recording 20 strikeouts and 1 walk in 12.1 innings. Bailey (11-10) hasn’t suffered a loss in his last nine starts dating back to July. In Homer’s ten losses this season, the Reds scored a total of 11 runs. With seven strikeouts on Saturday, he’ll pass the milestone of 200 Ks.

Sun 1:35 Age IP K/9 BB/9 SwStr% ERA FIP xFIP SIERA GB%
Bronson Arroyo (R) 36 192.1 5.57 1.45 6.0 3.56 4.08 3.89 4.09 44.5
Jeff Locke (L) 25 165 6.75 4.46 8.3 3.27 3.93 4.17 4.52 53.1

Bronson Arroyo keeps plugging along, having an excellent season. If he goes 7.2 innings he’ll reach the 200 IP mark for the the eighth time in the last nine seasons. The one year he missed (2011) he had 199 IP. Arroyo’s one start against the Pirates this year was a no decision in June when he gave up one earned run in 7 innings.

Jeff Locke is living, breathing proof why you shouldn’t fully trust ERA as a measure of pitcher performance. He has a low strike-out rate and one of the league’s worst walk rates. The gap between his ERA and advanced metrics is enormous. According to his xFIP and SIERA (4.52!) he’s been one of the worst starters in the NL. Back in June, I wrote that Locke’s peripherals didn’t support his glittering ERA of 2.19. He eventually struggled to the point where the Pirates demoting him to AA in late August. My guess is he’s making this start because he’s a lefty.

The Pirates’ Bullpen

The eighth and ninth innings were a strength for the Pirates for much of the season. But an injury to closer Jason Grilli, has shortened their pen by an inning. Grilli was sidelined on July 22 with a right forearm strain (yikes). He has been largely ineffective in his five appearances since returning from the DL. Mark Melancon, who was their eighth-inning specialist extraordinaire until Grilli’s injury, moved into the closer’s role and overall has done well. He’s converted 14 of 16 saves chances. Tony Watson and Justin Wilson remain the lefty-on-lefty specialists, both enjoying a solid season.