The Seattle Mariners have been busy this offseason with 11 trades. Including their deal with the Cubs back in July when they acquired Dan Vogelbach, there are now four likely changes to their starting lineup for 2017. Jarrod Dyson from the Royals and Mitch Haniger from the Diamondbacks will be replacing Nori Aoki and Seth Smith in the outfield, a new platoon of rookie Vogelbach from the Cubs and Danny Valencia from the A’s will be replacing Adam Lind and Dae-ho Lee at first base, and shortstop Jean Segura from the Diamondbacks will replace Ketel Marte.

Let’s examine how these moves will impact their defense. The following table gives our projected Defensive Runs Saved (DRS) for 2017 for both the new additions to the Mariners lineup and the primary 2016 starters for each of their positions. We estimated the DRS for each projected 2017 starter by examining each player’s past DRS per number of innings for each position and projecting their DRS for the number of innings each player is expected to play. We then estimated how many DRS each former player might have had in the same number of innings. For Haniger and Vogelbach, we also factored in their minor-league DRS where Haniger saved eight runs in 2016 in right field and Vogelbach cost his team 14 runs at first base over the last two seasons.

We project that the four changes to the Mariners’ starting lineup will combine for 23 more Defensive Runs Saved in 2017 compared to the players they are replacing. The Mariners will see a big improvement in their outfield due mostly to defensive stud Jarrod Dyson, who finished tied for ninth overall in DRS with 19 last season. He saved runs for the Royals in all three outfield positions in 2016—nine runs in center field, five runs in left field, and five in right. His defensive versatility will make it easier for the Mariners to keep Nelson Cruz out of the outfield and play him strictly as a designated hitter. Cruz played 48 games in right field in 2016 and cost the Mariners three runs.

The Mariners also improved their depth by adding Carlos Ruiz from the Dodgers to their bench replacing Chris Iannetta as the backup catcher. In 2016, Ruiz saved the Phillies and Dodgers a total of four runs in 56 games, whereas Iannetta cost the Mariners 10 runs in 93 games.

First base is a different story. Adam Lind and Dae-ho Lee were not very good last year (-5 DRS between them), but the new Dans at first base (Vogelbach and Valencia) project to be even worse. Vogelbach, the left-handed part of the likely platoon, lost 10 runs defensively at Triple-A last year, ranking 35 out of 35 qualifying first basemen in DRS. Valencia hasn’t played much first base, but he also ranked 35 out of 35 among qualifying MLB third basemen with -18 DRS for the A’s last year. We’ll project the combo at -15 DRS for 2017.

Even though the Mariners could see a decline in their first base defense, all in all, their trades have created a very positive defensive outlook for the Mariners in 2017.