It's often said that the winner of the NHL's unrestricted free-agent frenzy is the team that stays away from bloated unrestricted free-agent bidding.

You know who would disagree with that? General manager Doug Armstrong of the St. Louis Blues. He signed center Tyler Bozak last summer. He signed winger Patrick Maroon. Both of them played integral roles in the Blues' march to their first Stanley Cup championship this spring.

Then again, the Blues also signed Chad Johnson to be part of their solution in goal. He lasted 10 games.

Hence, investment in free agency is an imperfect science, but there are logical approaches to it, such as in our tiered look at the unrestricted free-agent market.

It breaks down the unrestricted free agents into categories ranging from sure things to big gambles to players to avoid like they're marinated in toxic waste. We also list the players who won't cost much and can spackle over problems.

Here's a look at the key players hitting the market on July 1. We left out players who appear primed to sign with their old clubs (Petr Mrazek, Maroon) or players who are likely to either re-sign or retire (Justin Williams, Niklas Kronwall).

Note: Ages listed are as of June 26. Players are listed alphabetically within each tier.

Tier 1: The best bets

Sergei Bobrovsky, G, Columbus Blue Jackets

Age: 30 | 2018-19 cap hit: $7.425 million

Look, we know the last metric anyone should use to evaluate a goalie is wins. That established, Bobrovsky has 115 wins in the past three seasons, for a .605 winning percentage. That's phenomenal. He has a career .919 save percentage and 2.46 goals-against average in the regular season, and has started 61-plus games in each of the past three seasons. He answered any questions about his postseason valor with a .925 save percentage in 10 games this spring. The issue here is his age: There's no question he's worth a high average annual value (AAV) to solidify someone's crease, but would he be worth it when he hits his late 30s?