Whatever you call it, there's nothing more valuable for a baseball team than the ability to stop its opponent from scoring. Look no further than the two Midwest rivals who will meet for three games this weekend at Wrigley Field -- the Cardinals and the Cubs.
Generally viewed as a favorite to repeat as champions, the Cubs have been a major disappointment for the first two months of the season.
They are sitting one game under .500 and with a run differential of only +1 after winning 103 games and compiling a run differential of +252 last season. The key to their success was the best starting pitching and defense around, which contributed to them allowing only 3.4 runs per game.
"I honestly think it begins with starting pitching,'' Cubs manager Joe Maddon said. "That sets all that up for you. I thought it did last year.''
Two seasons ago, it was St. Louis that everyone in the National League Central was chasing, thanks mostly to its pitching and defense. The 2015 Cardinals limited opponents to only 3.2 runs per game, with the starting rotation ranking first in the Major Leagues with a 2.99 ERA. That was the key to a 100-win season.
But opponents scored 4.4 runs against the Cardinals last season, with the starting rotation seventh in the NL with a 4.33 ERA. The result was a slide to an 86-78 record, which left them one game out of a tie-breaker game for a Wild Card spot.
It was a grind all season, thanks in part to the loss of Lance Lynn to Tommy John surgery and John Lackey being signed away by the Cubs. The worst part for manager Mike Matheny was that the Cardinals didn't play strong defense. Baseball Prospectus' ranking for Defensive Efficiency dropped them to 24th in the Majors, down from 16th the year before.
While Cubs starting pitchers compiled a 2.96 ERA last season, best in the Majors, the fielding behind them was even more off the charts. Anthony Rizzo, Jason Heyward and their compadres not only ranked No. 1 in BP's defensive metric but the gap between them and the second-ranked Blue Jays was bigger than the one between Toronto and the 27th-ranked Mets.
To have pitchers and fielders perform at those same levels again -- and work as well together, for that matter -- was unrealistic. The Cubs have made some roster changes -- most notably the departures of Dexter Fowler and Jason Hammel and the return of Kyle Schwarber -- but the biggest thing working against them is the unpredictable nature of baseball.
Maddon knew in Spring Training not to expect his team to pick up where it left off.
"I definitely believe it's going to be a different path to get to the end of the year and win it again,'' Maddon said Friday. "It's hard to imagine our starters pitching that well again. I definitely imagined a high level but how we pitched and played defense last year was almost a surreal level. There's got to be some regression.''
Opponents are scoring 4.6 runs per game off the Cubs this year, about 1.2 per game more than they did a year ago. That closely matches the difference the Cardinals experienced from 2015 to '16, and that led them to a decline of 14 wins.
It's too early to know if the Cubs will stay at their current level all season. Maddon expects improvement in every phase, except perhaps the job that his bullpen is doing. But if the Cubs stay right there with the Cardinals' 2015-16 model, winning 14 fewer games than a year ago, they would go 89-73 and fight all September to grab a spot in the postseason.
That's quite a fall from the cruise they were on last season. If they want to avoid the drama, they need to have a whole lot more victories like the one on Friday, when Lackey and the bullpen got enough big outs to beat the Cardinals, 3-2.
"I'd be much more concerned [about the record] if we were hitting and we were pitching well, but we're not,'' Maddon said. "There's room for improvement, getting back to what we normally look like, and that's what I'm looking forward to.''