For this relief much thanks.
—William "Author" Shakespeare, "Hamlet"

There is a certain relief in change, even though it be from bad to worse!
— Washington "Julius" Irving

Relief pitching has been evolving ever since Harry Wright first inserted himself to spell a faltering starter back in the early days of the National Association, the stepfather of today's National League. Today, team's have closers, left-handed setup men, right-handed setup men, long relievers, situational lefties…we've gone from 10- to 12-man staffs since five-man rotations became standard. Teams are approaching, on average, four pitchers per game (3.71 last year up from 3.55 at the start of the decade).

But how do we know that all this effort has made any difference?

Are teams better off now? Do they hold leads any better than they did in the past? And if they do, does anyone know it?

Well, ever since I started delving into Retrosheet's game log data, I have been pondering how to answer those questions. I think I have the answer.

Taking the linescore data available, I was able to determine the games in which teams gained leads and how and if they retained them throughout baseball history. I did this for teams leading at the end of the sixth, seventh, and eighth innings in various situations. What follows are the results mostly in tables as is my wont.

It looks like the state of relief pitching is as strong as it's been since the dead ball era when complete games were prevalent and relief pitching was waiting for John McGraw to rediscover and reinvent it. Teams in the first half of the 2000s have been retaining leads at a 78% clip even as ties after six innings have become rarer and rarer (12.40% in the 2000s is the lowest ever) and scoring is still at record highs.

However, given the high scoring a 10-0 lead after six that ends up a 12-9 win would constitute holding a lead. Let's look at the lead-retention percentages, instead, based on the situation at the end of the sixth inning:

So retaining one-run leads has not improved since the dead-ball era, and the results for the others have stayed at about the same level for decades. We have just seen bigger leads at the end of the sixth, which are easier to hold.

It seems that all the specialization in the bullpen has not really improved a team's ability to hold a lead. Though there are of course other benefits like saving a starter's arm and creating more opportunities to second guess a manager.

Next we will look at those situations that more closely examine closers and key setup men, and we'll look at which teams have been the most effective at holding leads. But that's for manana.