I have a guy i am acquiring in trade who was called up to the bigs after 25 games three seasons ago. He spent the last two seasons entirely in MLB and then was sent down to AAA near the end of last season. He still has an Option left. His service time is 2.161 season. His salary this season is $378K

If I start him in AAA this season and then call hip up after 25 games, will he be an arb guy next season....or still pre-arb?

Guessing you are in preseason mode. The other team already did the work for you by keeping him down for 25 games. You don't need to start the guy in Triple-A. He will be arbitration-eligible next season unless you keep him in the minors all season. Arbitration kicks in after 3 years of major-league service. The decimal point you see is days. So this player has 2 years, 161 days of major-league service. There are approximately 185 days in an HBD regular season.

I may be off on the digits a bit. But my understanding is that a guy is arb eligible if he starts the season with more than two years plus 159 days. I think the HBD regular season is 180 days, and 21 is the magic number of days to leave a player down. (I don’t have this in writing, just going from memory here). This would equate to 2.88 years of service.

So by my math you’d need to keep him down for at least 51 days (just over 28% of the season) to avoid him hitting the extra .72 years of ML time that he needs to trigger arbitration next year. But again, this is back of the envelope calculating based on my memory of how this works. And I could be off by a few days.

By the way, I have no idea why the previous owner sent your guy down to AAA at the end of his third season. If it’s after roster expansion it’s not like they needed the roster spot. And if he’s good enough that you’re planning to keep him, it seems silly that they demoted him and risked a ratings hit.

Actually your plan may not work even if you do leave him down for 50 games.

https://www.whatifsports.com/hbd/pages/Correspondence/FAQ.aspx

that link has a question about service time, and per the developers, a player will accumulate big league time for every day on an option assignment longer than 20 days. So if you leave him down in the minors for more than 20 days, he’s still getting minor league time.

BTW, the same question says it takes 172 days to qualify for a year of BL service time, which is a number I haven’t seen before.

The 172 is the number used in real-life MLB, so that makes sense. MLB regular season is 187 days, which is why teams will manipulate service time by keeping a guy down for more than 15 days. In HBD, you want to keep a player down 20 minor-league days.