The Nashville Predators met the Blue Jackets in Nationwide Arena last night. The respective coaches, old friends Barry Trotz and Ken Hitchcock, are two of the most prolific trend-buckers in professional sports.

Trotz has been standing behind the Nashville bench since the team played its first game in October 1998. Among current NHL coaches, only Lindy Ruff -- hired by the Buffalo Sabres in 1997 -- has served one team for a longer span.

Hitchcock came aboard in Columbus in November 2006, which practically makes him a lifer by present NHL standards. He has coached 281 games over 26 months -- and he has the sixth-longest tenure in the league. Imagine that.

Bobby Cox, Jerry Sloan, Jeff Fisher there are few lifers remaining in any realm of major-league sports. Over the past two years, there has been a 50 percent turnover among coaches in major-league baseball, the NBA and the NFL. But the hot seat is hottest in the NHL.

Twenty-two of 30 NHL coaches have been replaced since June 2008. That's a 73.3 percent rate of fire in a stretch of 18 months. Every arena in the league has a cannon of one sort or another, and plenty of powder.

There are a number of reasons why modern managers, regardless of the sport, have developed itchy trigger fingers. The most prominent of these reasons is inflation. Tickets are so expensive -- the average price is around $50 for a single seat at a major-league event -- that there is a greater win-now impetus, if only to maintain interest. The NHL, which has a greater reliance upon its gate receipts than other leagues, feels this strain most acutely.

Further, there is a force at work that applies unique pressure to NHL coaches. In a word, that force is youth.

Since a salary cap was implemented coming out of the 2004-05 lockout, young players have become more proliferate in the NHL. Entry-level contracts come with their own salary restrictions, giving cap-conscious GMs a ready source of cheap labor. As a result, young players are being pushed to the big stage as soon as possible.

The heat gets turned up when these young players come up on their second contracts. Those who are deemed talented enough are signed long-term -- to define a young core, save money, or both. The Pittsburgh Penguins are a classic example of this. They locked up Sidney Crosby, Evgeni Malkin and Jordan Staal as soon as they could. They provided themselves some cost certainty in defining where the bulk of their money was going to be spent. They structured their roster so as to avert the most expensive forays into future free-agent markets.

If teams are going to pay long money on second contracts, it follows that the players who sign these contracts are expected to fill important roles sooner rather than later. Crosby & Co. are a textbook example of talented young players stepping nicely into such roles. The Penguins fired a tough coach, Michel Therrien, and elevated a softer, younger Dan Bylsma to achieve this result. And they won the Stanley Cup.

This sort of thinking now prevails. If a coach fails to extract the maximum from his young charges, said coach is in trouble. Last month, St. Louis fired Andy Murray for the stated reason that the young Blues -- T.J. Oshie, Erik Johnson, David Backus, et al -- were not progressing.

In my opinion, Therrien (pig-headed) and Murray (neurotically detail-oriented) brought on their own dismissals. But the general idea remains: Young players are now expected to carry teams, and if they fail, the guy behind the bench gets fired.

Not too long ago there were some accepted axioms: Every team has a bad month, or a bad season; every coach's record is more or less determined by his goaltender; changing coaches rarely gets a team closer to a Cup, especially in an age of parity.

There are a few outposts where these verities are still self-evident. What is important in most places is the relative health of the young players -- on the stat sheet and between the ears. Old-line bosses will either reach their children or reach for the door. And yes, this includes Hitchcock.

Michael Arace is a sports reporter for The Dispatch.

marace@dispatch.com