One of the things that made Andrej Sekera attractive to the
Oilers last summer—besides being the best defencemen on the free agent market—was
versatility. He’s a two-way defencemen who does a little bit of everything and
has experience playing both sides of the ice.

Given that experience, should Edmonton plan to bump him to
the right side of its defensive depth chart, thereby clearing space on the left
side and filling a need on the right?

It’s a move which makes good sense, provided that
performance doesn’t suffer. Sekera could fill a top-four role on the right
side, which would leave the Oilers with only one spot to fill at the position
(assuming that Mark Fayne, currently under contract, takes the third job). That
would also allow Edmonton to look at left-shot free agents to fill a top-four
role on the portside, and there are several available (Brian Campbell and Dan
Hamhuis come to mind) who might be persuaded to take a shorter term deal.

The trouble is that we know handedness matters. NHL coaches
have long believed in placing right-shot defencemen on the right side and
left-shot defencemen on the left side whenever possible. More recently, a study
confirmed
that long coaching belief has value, with defencemen’s teams generally
suffering a penalty between 6.0 and 7.0 Corsi events per hour to play a skater
on his off-side. That’s a massive number; I was surprised when I saw it, and I
want to dig into it in greater depth this summer. If it’s anywhere close to
correct, teams should almost never play defencemen on their off-side.

It seems possible, however, that experience can compensate
to some degree for the disadvantage. Sekera is a veteran defenceman with experience
on his off-side, and seems like the kind of player who might be able to
outperform those numbers. To see if that was true or not, I decided to use Puckalytics
SuperWOWY function to see
how he’d performed over the years with right and left shots.

Sekera spent a fair bit of time on the right side last
season. He spent at least an hour with four different partners, two of which
were right shots and two of which shot left. The Oilers’ on-ice results with
those four different defence pairs are revealing:

If we combine the right-shot numbers and left-shot numbers,
we find that the Oilers improve by 11 shot attempts and 0.2 goals per hour when
Sekera plays with a right-shot defenceman than they do when he plays with a
left-shot defenceman, and they do it despite taking an additional defensive
zone shift per hour.

Davidson’s numbers are particularly compelling. There’s an
argument that Nurse simply wasn’t ready for NHL action last year, but Davidson
was excellent away from Sekera. Some of the issue is that we’re looking at a
small number of minutes and a lot of defensive zone starts, but Sekera/Fayne
had a lot of own-zone draws too and was manifestly a better pairing (Nurse and
Schultz both had easier zone starts when with Sekera).

Still, it’s only one year. During his time in Carolina,
Sekera played almost exclusively with right-shot defencemen, with Justin Faulk
his primary partner. That makes it difficult to compare his performance with defencemen
of different handedness.

If we go back to his time in Buffalo, though, that changes
dramatically. Sekera spent at least an hour between 2007 and 2013 with 11
different partners, with four of them being right shots and seven of them
shooting left.

The list looks like this, ranked by total ice-time:

I don’t see a massive talent gap there, and Sekera actually
had pretty good results with the two most suspect players on the list (Gragnani
and Paetsch) in short stints together.

That makes the results pretty interesting. With Sekera and a
right-shot defenceman on the ice, the Sabres averaged four more shot attempts
per hour than their opponents. With Sekera and a left-shot defenceman on the
ice, they were one shot attempt shy of the opposition. That’s a five-event
swing per hour altogether, which is just a touch shy of the Hockey Graphs study
linked above.

I think the actual performance swing is a little bit smaller, because
Sekera/righty had a more favourable ratio of offensive-to-defensive zone draws
than Sekera/lefty did. In an average hour, the former had two extra shifts
starting in the offensive zone than the latter did.

Even so, it seems pretty clear that Sekera has historically
had more success playing on his right side than on his left. That fits with
what we saw last year, and suggests that Edmonton would be well-advised to keep
Sekera on the left side. It also suggests that the Oilers would do well to add
two right-shot defencemen to the roster, and three if they move Fayne.