Behind the numbers: How long can Jonathan Toews maintain his excellence?

What once looked like a legendary career in gradual, inevitable decline took a surprising and welcomed turn in 2018-19.

Jonathan Toews, in his 12th NHL season at age 30 (now 31), set career highs in goals (35), points (81) and shots on goal (235), and also turned in his best performance since the 2015 Cup-winning season in terms of Team Point Shares, an all-encompassing statistic created by Hockey Reference that measures overall offensive and defensive contributions to team success.

Toews’ fantastic, age-defying performance happened in the face of a shift in accepted opinion — backed by numerous studies — that the peak age for NHL forwards is more like 24 or 25, rather than 28 or 29. Beyond that point, most forwards’ careers begin steady declines that accelerate once they hit their 30s.

That disconnect raises a few crucial questions. Firstly, was Toews’ 2018-19 campaign an anomaly in a descent, or a permanent return to form for one of the league’s most durable, well-rounded stars?

The fact that, prior to this season, Toews’ points per game and Team Point Shares per game had declined year-over-year four of the past five seasons is a substantial indicator of long-term decline.

But then again, Toews’ shooting percentages in 2016-17 and 2017-18 — 10.6 and 9.5 percent, respectively — demonstrated that some bad luck was also a factor, and his 14.9 shooting percentage in 2018-19 (combined with a high shot attempt frequency) was much more in line with his career 14.1 average.

The answer probably lies somewhere in between anomaly and new standard.

Secondly, how long will Toews be able to maintain top-six quality play for the Blackhawks, even if some degree of decline occurs?

To project the rest of Toews’ career arc, we can look at two pools of relevant player comparables (dating back to 1990): Pool A includes 35 forwards who had similar age-30 seasons to Toews, and Pool B includes 26 forwards who had similar production to Toews through their first 12 seasons combined. From the two pools, we can make a model of their average production in the seasons beyond where Toews lies in his career — for Pool A players, their age 31, 32, 33 and so forth seasons; for Pool B players, their 12th, 13th, 14th and so forth seasons.

As expected, both models show steady decline, even though many current and future Hall of Famers are included in both pools — in the war of age vs. talent, even Jaromir Jagr eventually lost.

Toews scored 81 points in 82 games this past season, for a per-game average of 0.99, and produced about 0.1 Team Point Shares per game, as well.

Based on the models of comparable career trajectories, Toews’ offensive production and overall game impact should be expected to decline 20 to 25 percent over the next three years, and continue on at a similar rate beyond that.

Of note, however, is that the models really don’t predict an enormous bottoming-out, when compared to league-wide medians. Even seven years out, players who were once in similar situations to Toews — those who haven’t retired yet, that is — still produce points and Team Point Shares at strong second-line caliber rates.

So, a key takeaway: When forwards keep up first-line level production and impact this far into their careers, most maintain at least second-line level production and impact until they retire.

Take Mats Sundin, for example. In 2001-02, the Leafs center tallied 80 points in 82 games at age 30, in his 12th NHL season — almost identical in every way to Toews. Sundin continued to produce 70-point campaigns for the following five seasons, with little drop-off at all.

Markus Naslund is another apt comparison. In 2003-04, the Canucks winger scored 84 points in 78 games at age 30, in his 11th NHL season. His point totals descended to 79, then 60, then 55, then 46 over the next four seasons, but remained top-six level nonetheless.

If Toews can avoid major health problems, which he hasn’t been plagued by since his 2012 concussion saga, the Hawks captain’s ability to sustain excellence for 12 seasons is a very promising indicator that he’ll be able to maintain it for perhaps another half-dozen more.