Prior to the start of MLB's owner-imposed lockout last month, there was a free-agent frenzy unlike anything we've seen in recent baseball history. Maybe even in all of baseball history. Half of the top 50 free agents signed before the lockout, many in the week leading up to the expiration of the collective bargaining agreement. Signings came fast and furious.

The teams that signed those free agents hope those players will help them win a championship, or at least not decline to the point where they're a detriment. Free agency is a risky game. Spend smart and it can pay off immensely. Don't do your homework and you can be left with a contract that eats up payroll and reduces your chances at a title.

With that in mind, let's take a look back at each team's best free-agent signing ever. To do that, we have to first set some ground rules. Here they are:

Players who changed teams only. We're only going to look at players who left one team and joined another. Players who were traded to a new team and then re-signed with that team don't count, like Mike Piazza with the Mets.

Major league players only. Players who signed and then spent several years in the minors don't count, like Aroldis Chapman with the Reds. We're looking at players who stepped right onto their new team's MLB roster.

Entire tenure matters. We're going to focus primarily on the initial contract, but if a player signs a one-year deal and it turns into a long-term tenure, the other years are considered too. Think Dexter Fowler with the Cubs.