In reference to a Wallace Matthews article from the other day, I decided to take a look at how much our starting staff helped the bullpen during the dynasty years compared to the last five.
From 1996-2000, Yankee starters went at least six innings 535 times, averaging 107 times a season.
From 2004-2008, the starters went at least six 494 times, averaging 99 times a season. Not as big a difference as I expected. But you see the real difference when you kick it up to seven innings, when the difference jumps to 118 occurrences (24 times a season). That is a lot.
And what about total starter innings per year?
2004 - 942.1
'05 - 965.1
'06 - 933.2
'07 - 921
'08 - 898.1
making for an average of ~932 per season.
What's perhaps most disturbing is that it's gone down every year since 2005.
Now the dynasty years:
1996 - 921.2
'97 - 1017.1
'98 - 1061.1
'99 - 1002.2
'00 - 964.2
making for an average of ~993.5 per season.
Pretty big difference: 61.5 ip/season equates to 185 more outs each year that the bullpen must get.
Not just that, but the starters were better then too. Going by Adjusted OPS Against (because BRef doesn't have ERA+ for team starters' totals):
'96 - sOPS 99 - pen sOPS 88 - result: title
'97 - sOPS 94 - pen sOPS 84 - result: lost in rd. 1
'98 - sOPS 82 - pen sOPS 92 - result: title (best team ever?)
'99 - sOPS 90 - pen sOPS 82 - result: title
'00 - sOPS 96- pen sOPS 90 - result: title
average starter sOPS ~92
average reliever sOPS ~87
So the dynasty Yankee starters were better than league average every single year, and they were utterly dominant in the magical year of '98. The bullpen was also great during those years.
'04 - sOPS 98 - pen sOPS 100 - lost in rd. 2
'05 - sOPS 102 - pen sOPS 98 - lost in rd. 1
'06 - sOPS 91 - pen sOPS 97 - lost in rd. 1
'07 - sOPS 99 - pen sOPS 102 - lost in rd. 1
'08 - sOPS 101 - pen sOPS 87 - missed playoffs
average starter sOPS ~98
average reliever sOPS ~97
So the Yankees have still had better than average starters recently (which makes sense - they have made the playoffs four of five years), but had just one great year ('06). Outside of that, it's a bunch of mediocrity. The same can be said for the bullpen, which has had one great year ('08) in the last five.
Can a great bullpen really be as or more valuable than a great starting staff (as Matthews would have us believe)?
This year, the Yankees had a phenomenal bullpen (87 sOPS), yet missed the playoffs. The starters were mediocre (101 sOPS), so even a great bullpen couldn't save the season. Meanwhile, the bullpen sucked last year (102 sOPS), yet we made the playoffs with the same mediocre starters (99 sOPS).
In that special year of 1998, the bullpen was the worst it ever was in that span (92 sOPS), but the starters were phenomenal (82 sOPS).
Is it just a coincidence that when the Yankees had solid starters every year, they won three of four titles, but haven't even been back to the Series with mediocre starters? Doubtful. And that's not even counting that starters have more impact because they pitch more innings.
Admittedly, there is an argument to be made that the largest disparity between the dynasty and current Yankees has been the bullpen (10 sOPS points worse compared to just six for the starters). But is that really a case of poor relievers? It's more likely that the pen has been leaned on too much due to less innings from starters.
2008 throws a wrench into the equation. The '08 pen pitched the most innings for the Yankees in any year I studied, yet it also had it's best year since 1999 (but that's probably more an indictment of Joe Torre than anything).
Sorry that there's no definitive conclusion. The Yankees have won with medicore starters and a great pen ('96), but have also missed the playoffs with that same combination ('08).
What I need to look at sometime is the correlation between starter innings and bullpen effectiveness. I would expect that the longer starters go, the better relievers do. Also, does a great bullpen make starters better (because they don't have to pitch as long)?