Last week, the Minnesota Twins announced they agreed to terms with free agent Josh Donaldson. The third baseman is getting a four-year deal worth $92 million guaranteed. Donaldson's pact qualifies as the largest free-agent signing in franchise history, and as the big splash the reigning American League Central champions had attempted to make at other points this winter.

To help pass the time until Opening Day (and hopefully sate appetites), we intend to spend the rest of the winter profiling the offseason's biggest additions and figuring out what makes them so effective. Today, that means surveying the three reasons Donaldson should be a welcomed add.

1. Power

Just what the Twins needed, right? Last year, they broke the single-season homer record. Now, they've added Donaldson, who has homered 30-plus times in four of his last five seasons, and in all four of his most recent campaigns in which he played in more than 100 games.

Donaldson's 78 home runs over the last three years ranks eighth among full-time third basemen. (Funny enough, Miguel Sano ranks ninth.) Everyone ahead of Donaldson on that leaderboard appeared in at least 100 more games than he did, too. Predictably, he fares better using ISO, a rate statistic designed to suss out power production. Donaldson checks in at third, behind Nolan Arenado, and yes, Sano.

The Twins have two of the premiere slugging third basemen in the game -- one of them just won't be playing there anymore.

2. Defense

One benefit of the Donaldson signing is how it allows the Twins to shift Sano to first base. Sano is a well-below-average defender at the hot corner, and was a big part of the reason why Minnesota's infield defense ranked 23rd last season in converting grounders into outs. The Twins ought to fare better in that regard in 2020.

Public defensive metrics are notoriously untrustworthy, but they suggest there is indeed a sizable gap between Donaldson's leather and Sano's. Defensive Runs Saved have Donaldson worth an average of 12 more runs defensively per season over the last three years. Statcast's new defensive metric, meanwhile, has Donaldson worth nearly six more runs per season.

Depending on where exactly Donaldson's and Sano's true-talent levels fall, the Twins could be gaining between half and a whole win just based on defense. (Obviously this analysis assumes Sano isn't a complete mess at first base when compared to C.J. Cron, so adjust as one sees fit.)

3. Overall production

Donaldson is an above-average hitter and fielder who plays an important defensive position. You already know -- or, should be able to infer -- that his catch-all metrics look good, too. How good? Since 2017, he ranks 27th in Wins Above Replacement. That puts him in company with J.T. Realmuto, Joey Votto, and Manny Machado, among other star-level performers. (And remember, he ranks there while missing significant time in 2018 due to injury.)

Donaldson's age (he turned 34 last month) could come into play during the second half of this deal. But, for the time being, the Twins have added a potential impact-level player who should be a boon for the middle of their order and their infield defense.