CalClutterbuckNYI by Lisa Gansky. Licensed under Creative Commons via Commons.

I was listening to this great episode of the PDOCast in which the guys discussed the recently waived Alex Semin and had a couple of additional thoughts on evaluating fourth liners, and on how the mold of the bottom-six forward has evolved over the years.

First of all,  I don’t believe in ever dismissing conventional hockey wisdom. There is wisdom in experience, and guys who have been around hockey for a long time have deep insight that can shed a lot of light on the game. Let’s take fighting for example. A former player might tell you that a good fight can swing momentum, and a quant might (very many have) dismissively wave them aside.

“There is no proof of that. Run along now.”

Well a couple of points. First of all, absence of evidence does not equal evidence of absence. It’s something that baseball quants have discovered over and over again, forcing them to retract many extreme statements  made in the early days of analytics (see catcher framing). This phenomenon is already happening in hockey with shot quality and expected goals. It will continue to happen. A word of advice to fellow analysts and quants: Hockey people are never wrong about something having an impact….they are just often misguided regarding the weighting. Biases can do that to the brain. We’re all guilty of it.

This is important when it comes to evaluating fourth liners. Conventional wisdom says that you need those players to be bangers, energy guys, etc. Analysts would contest that you simply want the best players, as evaluated by who drives goal output.

But the reality is somewhere in the middle. How so?

1. Hitting for the sake of hitting can have an impact, it’s just usually overstated.

Whether you’ve played in the NHL, or played in high school, or even simply watched hockey, you know that momentum is a legitimate concept. You can feel it. The issue with momentum is measuring it, or rendering it useable in evaluation. But when you watch an NHL game, you can tell that big hits CAN change momentum. Hockey people aren’t wrong about that, but the eye is drawn to the big hit, or the big event, and fails to remember the more subtle shifts or plays, such as a poor fourth line being hemmed into its zone for two minutes. So the impact of physicality is usually overstated. That said, hitting is at worst a decent tiebreaker. If you can find players that can drive play, contribute positive goal differentials, and also hit and swing momentum when needed, or set the tone to start a big playoff game, that’s always preferable to a line that only checks those first two boxes. Often those players are good leaders and locker room guys as well. There’s another good tiebreaker.

The New York Islanders found a fourth line that can do all of those things pretty well, and it’s worked for them. The Tampa Bay Lightning have gone with a slightly different model. They would probably love a guy like Cal Clutterbuck on their team, but they weren’t willing to substitute in somebody who would cost them in terms of driving play, so they went with the next best thing (or based on the numbers, maybe even something better), a purely possession-driving line, with some skill. Chicago the last few years has favored severe fourth-line deployment, placing Marcus Kruger with interchangeable all-around reliable players to soak up defensive zone starts, limit chances against top lines, and allow offensive teammates to thrive in offensive deployment against softer competition.

These models all work to different extents. The common thread is that these players are legitimate NHLers outside of their hitting or leadership qualities. “Intangible” factors such as those aren’t irrelevant, they simply need to be closer to being tiebreakers than primary evaluators.

2. Fourth line chemistry can be the most important kind

This is another under-discussed concept when it comes to data analysts. Chemistry is a real thing. It can often be clouded by variance, so tread lightly when it comes to rash decisions based on a perceived lack of it, but it is important. One of the ways in which chemistry can be most apparent is when it comes to fourth liners.

I believe that purpose and confidence are huge factors when it comes to a line’s success. This is often displayed on the power play, where units who understand how they are supposed to enter the zone and the manner in which they are most likely to score tend to have the most success.

This is generally less of a factor with top even-strength lines because they are put together for longer, are teammates for longer, know each others’ strengths and weaknesses for longer, and also know their role is to score goals. For fourth lines the role can be less obvious.

Chicago’s fourth line knows its role is to shut down the opposition and create space for its scoring forwards. Tampa’s fourth line knows it needs to eliminate opposition chances by keeping the puck, as well as chipping in goals when they get the chance. New York’s trio knows hitting is a priority (Clutterbuck and Martin have been the league’s two hit leaders consistently over the past half-decade), but that chipping in dirty goals and playing responsibly in maintaining leads is also a priority.

The latter unit also works particularly well because it is composed of three like-minded players with similar skill sets. They get the puck deep, cycle it and wear down the opposition with physicality and determination. A fourth line of Alex Semin, Vlad Namestnikov and Daniel Sprong would do things a little differently. But at least they would all be of the same mindset and would be able to keep up with each other.

The point is, a fourth line of Alex Semin, Marcus Kruger and Matt Martin would struggle, at least at first. And fourth lines are given very little leeway, and less ice time to develop chemistry than top lines. They need to be comfortable together and successful almost instantly. So having guys that work well together is a huge advantage.

As a GM, I would want to work with my coach in the offseason on determining exactly what kind of game the team will be playing, and how the fourth line can best be used. At that point, I would want four or five guys, and a couple more in the minors, who could slot in to that role.

3. Even-strength differentials are not everything

One final point on this is that quantitative analysts have a tendency to equate “even-strength aggregate shot/goal differentials” with “hockey results.” But hockey is far more situational than that. A team needs players who can kill penalties, many of whom tend to be less skilled and more conventional fourth-line type players.

NOTE: There is, however, a bias in conventional hockey thought towards assuming that such players are good penalty killers. Skilled guys like Max Pacioretty and Erik Karlsson were assumed to be poor penalty killers (and in many cases this is still assumed) but have proven to be elite in such situations. Still, they are likely closer to exceptions than the rule. Often you need defensive type players to play in those situations.

There also becomes a point in the third period with a lead where it is advantageous to play lower event hockey and minimize big chances against rather than simply win the differential battle. Defensive-minded and responsible fourth liners can also come in handy here (though again, this isn’t always the case). A coach and GM must also keep those situations in mind when determining roster construction.

Takeaway

There is more to building a hockey team than simply tossing out the players with the best even-strength shot or goal differentials. Factors like hitting ability; leadership; chemistry; and special teams and lead protecting capabilities, though overemphasized by TV analysts and some front offices, still must be taken into account. Build responsibly.