Rotten rotation remains at heart of Twins' troubles

The term "outlier" is so useful that it tends to get overused. At the risk of doing so, let's try it on in a couple spots here in a brief discussion of Twins starting pitching.

Of all the discouraging things that have happened over the vast majority of the past six Twins seasons, poor starting pitching feels like it's at the top of the list. Something that was a relative strength during some of the Twins' six division-winning seasons between 2002-2010 and at least not a hindrance in the others has become a never-ending problem from 2011 to present.

Poor free-agent decisions, a lack of pitching development from the minors and some injuries have contributed to the mess. So, too — perhaps — have been some flickers of hope in the wreckage that gave fans and the team false hope. Here's where we get into outliers.

Check out the ERAs of Twins starting pitchers for the past six seasons and where they ranked in MLB:

2011: 26th at 4.64

2012: 29th at 5.40

2013: 30th at 5.26

2015: 16th at 4.14

2016: 30th at 5.47

In five of those six seasons, the Twins were in the bottom five of the majors. And yes, in three of those — including this year, thanks to a dreadful August — they have been dead last. You'll notice the blip in 2015, when they were decidedly average. The relative success of the staff last season brought optimism for 2016.

The optimism wasn't necessarily unfounded since some of the pitchers in 2015 were different from those who had failed for the Twins in years past. Nevertheless, 2015 sure seems like the outlier right now — the one statistical member of the group that doesn't fit and is not representative of the whole.

Same goes for the starters' ERAs by month this season. April: 4.40, 6.22 in May, 6.05 in June, 3.98 in July and 6.97 in August.

July is sure looking like the outlier, both in terms of starting pitching and the Twins' overall play. They had seemingly rescued themselves from a disastrous season to merely be bad; instead, they are now 49-78, on pace for a 99-loss season that would match the one which started the mess in 2011.

It's hard to think there's any immediate relief in sight.

Ervin Santana has done a very credible job this season, compiling a 3.33 ERA. The veteran righthander is under contract for two more years and is the only one close to a sure thing right now.

Every other Twin who has started at least four games has an ERA over 5.00 this season. That includes Jose Berrios, Tyler Duffey, Kyle Gibson, Phil Hughes and Hector Santiago — five guys who figure to be prime candidates to join Santana in next year's rotation.

Berrios and Duffey have been so bad — giving up a combined 20 earned runs in 15⅔ innings over the past eight days — that they were sent to the minors Thursday.