Host B.J. Koubaroulis runs through the top plays from high school basketball games in D.C., Maryland and Virginia. (Nick Plum for Synthesis/Koubaroulis LLC./The Washington Post)

At the end of the regular season, Reservoir Coach Michael Coughlan added up the total margin of defeat from the Gators’ five Howard County losses. When the math was finished, Coughlan had the number he would use to motivate his team: 22 points.

The Gators lost to River Hill, the second seed in the Maryland 3A East region, by six points. They lost twice to Oakland Mills, which went undefeated through the regular season and was the top seed in the Maryland 2A East region, by one point and five points, respectively. Reservoir lost to both Atholton and Marriotts Ridge by five.

Now, with the Maryland state semifinals set for Thursday, none of those teams that beat Reservoir in the regular season remain in contention. Only the Gators, who lost so many close games this season, are still eligible to win a state championship.

“We kind of snuck up from behind. We ended up actually finishing third in the county by ourselves. A lot of people didn’t really realize that,” Coughlan said. “I told the kids we’re basically 22 points from being undefeated. It was big, kind of sneaking up at the end, because people weren’t really paying attention to us.”

Reservoir’s road to Thursday afternoon’s Maryland state semifinal matchup against No. 8 Potomac (Md.) was aided by upsets in the 3A East. Top-seeded J.M. Bennett fell in the second-round against Wilde Lake and River Hill was upset by Centennial, also in the second round. With the region’s top two seeds out of the way, third-seeded Reservoir managed to win the region title without playing a road game.

Including its three playoff victories, Reservoir will enter Thursday’s state semifinal riding a 10-game winning streak that began with a Jan. 28 win over Glenelg. The Gators advanced to the state semifinals by virtue of a 59-51 win in the East region final over Annapolis, a team that features a back court comprised of Juan Brown and Delazso Smith, two of the top guards in Anne Arundel County. That experience, Coughlan said, will be valuable against Potomac (Md.)’s Dion Wiley.

“Getting through our region first, I took a look at [Potomac] Friday night, and once I started looking I decided I’d get up Saturday. I didn’t want to depress myself anymore, so I got up Saturday to get going on the scouting,” Coughlan said. “I had three tapes on Annapolis before we played them and I thought we put together a really good plan because they have those two really good players. Obviously now, with Dion Wiley and the other guards, it’s going to be a step up.”