Here’s a little chart showing some details of the Toronto Blue Jays starting rotation over the years.

First column: year.
Second column: where their runs/game ranked compared to the league. (I wanted to use ERA or ERA+ but R/G is what Baseball Reference had in easy-to-get form so that’s what I used.)
Third column: how many pitchers made starts for them.
Fourth column: how many starts their top five pitchers made for them.

1977 13th 11 131
1978 13th 8 132
1979 14th 13 112
1980 10th 11 118
1981 11th 8 90
1982 4th 9 147
1983 7th 8 150
1984 6th 8 153
1985 1st 10 141
1986 6th 9 140
1987 1st 11 139
1988 6th 8 133
1989 4th 12 145
1990 3rd 11 141
1991 1st 11 137
1992 8th 9 136
1993 5th 8 146
1994 6th 7 110
1995 12th 10 110
1996 6th 11 128
1997 3rd 10 135
1998 4th 9 140
1999 9th 8 140
2000 11th 12 124
2001 6th 9 123
2002 9th 13 111
2003 10th 10 134
2004 8th 11 121
2005 6th 9 135
2006 5th 12 119
2007 2nd 11 128
2008 1st 8 139
2009 11th 12 127
2010 9th 11 127
2011 11th 12 116
2012 11th 12 113
2013 13th 13 121
2014 9th 9 144

Here’s the point of this chart. Look at the 2014 team compared to the teams right before it. Obviously, it’s a big improvement. The top five guys started 144 games; that hadn’t happened since 1993. Only nine guys made starts; that’s not common for the Jays, especially these days.

Now, the pitchers who turned in this performance were mostly the same guys whom the Jays had been counting on for the past few years: R.A. Dickey, Mark Buehrle, Drew Hutchison, Brandon Morrow, J.A. Happ. The results hadn’t been good in 2011 or 2012 or 2013, but in 2014 they were. Once Gibbons settled on a rotation of Dickey, Buehrle, Hutchison, Marcus Stroman, and Happ, the same five guys took the ball every day and performed consistently all year. What we saw in 2014 is what it looks like when those guys pitch and everything goes according to plan.

…But it wasn’t actually that great, was it? 9th in the league in runs per game; that’s not terrible, but it’s nothing to write home about. If 9th in the league is the best you can do, then the starting rotation is not one of your team’s strong points.

Four of those guys are going to be back in the rotation this year: Dickey, Buehrle, Hutchison, and Stroman. Happ’s spot will be filled by either Daniel Norris or Aaron Sanchez, or at least that’s what it looks like right now. I think it’s quite likely that this rotation will turn in worse results than last year’s, and here’s why:
– Dickey and Buehrle are at an age when it is unreasonable to expect drastic improvements, but sudden dropoffs in performance are always a possibility
– Hutchison pitched a lot last year, after coming off an injury. He’ll be doing well just to stay healthy in 2015
– Stroman was a rookie in 2014, and was fantastic. It’s not reasonable to expect more of him than he delivered last year
– Sanchez and Norris are untried rookies. It’s possible that they could do better than Happ’s perfectly decent 2014 season, but you certainly can’t count on it
– the starting rotation was disgustingly healthy in 2014. It’s not reasonable to expect that to last
– Stroman, Hutchison, Sanchez, and Norris are all young pitchers, and young pitchers will break your heart

Now, they’re all talented pitchers, of course; I haven’t named anybody who’s not worth trying in a major league starting rotation. I wouldn’t want to point at any one of them and say, “That guy’s going to fail!” But chances are someone’s going to get hurt. Chances are someone else is going to have a disappointing year for no particular reason. And then where are the Jays going to be?

Most of the discussion this off-season about the changes the Blue Jays need to make has focused on second base and the bullpen. (And for good reason.) People haven’t mentioned the starting rotation much. But I think the rotation needs the help just as urgently.