Baseball Reference provides these eerily similar 2018 projections for Xander Bogaerts and Seattle shortstop Jean Segura:
XB 589 PA, 13 HR, .292/.354/.433/.786
JS 552 PA, 13 HR, .292/.340/.437/.777
https://www.baseball-reference.com/players/b/bogaexa01.shtml
https://www.baseball-reference.com/players/s/segurje01.shtml
Over the past two seasons Bogaerts has posted 8.1 fWAR. valued at $54.3 million, in 305 games while Segura has posted 7.9 fWAR, valued at $53 million, in 278 games.
Segura, who is two-and-half years older than Bogaerts, remains under team control for five seasons at $70 million, with a team option for a sixth year, while Bogaerts is under team control for two seasons with a projected 2018 salary of $7.6 million.
Each faded in the second half of 2017:
1st Half
XB 82 G, 351 PA, .303/.359/.447/.806
JS 60 G, 273 PA, .349/.390/.482/.872
2nd Half
XB 66 G, 284 PA, .235/.324/.347/.671
JS 65 G, 293 PA, .253/.311/.375/.686
Nevertheless, Steamer600, which assumes 600 plate appearances for each hitter, projects 2018 WAR of 3.5 for Bogaerts and 2.1 for Segura:
http://www.fangraphs.com/projections.aspx?pos=ss&stats=bat&type=steamer600&team=0&lg=all&players=0&sort=27,d