The last three games have really highlighted the Leafs defensive woes, but the problem has been an ongoing one and a significant portion of the blame must be given to the Leafs top line.

On Puckalytics.com, you can find what I call “Percent of Team” statistics, which are nothing more than the percentage of all events by the team that the player was on the ice for (only counting games in which he played in). So, for example, we can see that Ryan Suter leads the league with a %ofTeam TOI of 45.44% this season, which means Suter has been on the ice for 45.44% of his team’s 5v5 ice time. The Leafs leader in %ofTeam TOI this season is Roman Polak at 36.55%, whereas a guy like Trevor Smith is at 16.36%.

Puckalytics.com has these Percent of Team statistics for TOI, goals for/against, shots for/against, fenwick for/against and corsi for/against (fenwick includes shots that miss the net and corsi includes shots that were blocked). By comparing Percent of Team Corsi Against with Percent of Team TOI, we can get an idea of which players are giving up shot attempts against at a higher rate than they are getting in ice time. Here are Leaf players for this season:

Player %ofTeam TOI %ofTeam CA Percent Diff PHIL KESSEL 29.29 33.86 15.60 JAMES VAN_RIEMSDYK 30.04 34.59 15.15 TYLER BOZAK 28.76 31.85 10.74 DION PHANEUF 34.52 36.36 5.33 ROMAN POLAK 36.55 38.45 5.20 KORBINIAN HOLZER 32.35 33.28 2.87 MORGAN RIELLY 32.01 32.89 2.75 JOFFREY LUPUL 28.27 28.85 2.05 STUART PERCY 30.77 31.01 0.78 CODY FRANSON 31.58 31.49 -0.28 NAZEM KADRI 29.04 28.87 -0.59 PETER HOLLAND 23.43 23.2 -0.98 DAVID CLARKSON 26.4 26.07 -1.25 STEPHANE ROBIDAS 31.46 29.82 -5.21 JAKE GARDINER 34.34 32.11 -6.49 LEO KOMAROV 26.18 24.45 -6.61 DANIEL WINNIK 25.59 23.65 -7.58 MIKE SANTORELLI 27.96 25.58 -8.51 RICHARD PANIK 17.83 15.44 -13.4 TREVOR SMITH 16.36 12.97 -20.72 JOSH LEIVO 16.18 12.78 -21.01 DAVID BOOTH 19.51 14.77 -24.30

Here Percent Diff is calculated by (%ofTeam CA – %ofTeam TOI)/%ofTeam TOI and is an indication of how many more shot attempts against they give up when on the ice than team average. Higher numbers are worse in this metric and thus the worst players are the top line and the defensemen given the tough minutes (Phaneuf and Polak).

Clearly, the top line is giving up way more shots than their ice time warrants and this is nothing new for these guys. If we include all 320 forwards with at least 1500 minutes of ice time over the last 3 three seasons plus the first couple months of this season, Bozak ranks 309th (+7.56%), Lupul 306th (+7.12%), Kessel 304th (+6.95%) and van Riemdyk 296th (+6.27%). This is terrible. Those four guys are in the bottom 25 players in the league (for perspective, the bottom 5 players are Manny Malhotra, Jim Slater, Gregory Campbell, Lauri Korpikoski and Chris Stewart).

I don’t want to suggest that these guys aren’t valuable players — for the most part they are due to their offensive production — but whatever offensive production they produce is largely offset by their terrible defensive ability. The good news is that, with some lineup optimization, the Leafs can probably fix this problem. Let me explain by looking at the following chart.

The chart above shows how the Leafs top 4 forwards have performed with this “Percent Diff” metric the past few seasons. There are three things that we should take note of:

1. Lupul has improved as he has played less and less with Kessel/Bozak and more with Kadri (and with Holland this season), especially when also playing with Winnik or Santorelli, who offer a good defensive presence.

2. JVR got worse as he has played more with Kessel/Bozak (2011-12, in Philly, he wasn’t too bad playing mostly with Jakub Voracek and Wayne Simmonds).

3. Kessel/Bozak have always played the majority of time together and have always been quite bad in this defensive metric.

This really should highlight the fact that Kessel/Bozak along with either Lupul or JVR have been really bad defensively. It isn’t that Lupul and JVR are incapable of putting up decent defensive numbers if given the right line mates. The top line has been killing the Leafs defensively the past several seasons.

So, the question is: If everything that has been tried so far has largely been a failure, is there a way to improve the Leafs top line (and overall line up) from a defensive point of view? In an ideal world, Leafs management would go out and find a quality top line player who can play at both ends of the rink, but that is far easier said than done. The alternative is to mix in more defensively capable players like Santorelli or Winnik with the highly skilled players.

The challenge in all of this is that it seems abundantly clear that the coaching staff has zero interest in splitting up Kessel and Bozak for any significant length of time, and from my perspective that might be the best solution; it dumbfounds me why the coaching staff keeps these guys together despite their astoundingly bad defensive stats. Honestly, wouldn’t it be nice to be able to evaluate a JvR-Kadri-Kessel line could do over a ~10 game stretch? Unfortunately, we haven’t been given that opportunity. So, if the current coaching staff has no interest in splitting up Kessel and Bozak for any serious length of time, the only other option is adding a defensively-reliable player to them and hoping that it won’t significantly negatively impact the offensive production too much. My vote in this scenario would be Santorelli because he can provide some offense as well. The first line in this scenario ends up being Santorelli-Bozak-Kessel. (As I write this, though, I am thinking that Santorelli-Bozak-JVR could be an intriguing option, too).

I’d then go with a second line of Kadri centering Lupul and Winnik, as Kadri and Lupul can provide the offense and Winnik can be the more responsible defensive player. The third line would then be Holland with JVR and some combination of Clarkson, Booth, or Komarov (when he returns).

My proposed top 3 lines would therefore be the following:

Bozak centering Kessel and Santorelli.

Kadri centering Lupul and Winnik.

Holland centering JVR and Clarkson/Booth/Komarov.

The result just might be a better balance of offense and defense throughout the top three lines as opposed to having a top line that is great offensively but is absolutely terrible defensively.