A group of 11-year-olds arrives to spend six weeks playing sports at Camp Avalon—which they affectionately call Camp Average, because they never win at any sport. And that's the way they like it. But this summer, new camp director Winston—who hates losing—has some hyper-competitive ideas about how to improve their performance, whether they want to or not! Led by main character Mack and his friend Andre, the boys of Cabin 10 decide to reclaim their summer and revolt by losing spectacularly at every game they play, and especially at the big baseball tournament coming up with three nearby camps.

It’s a new summer at Camp Avalon—which Mack and his friends still affectionately call Camp Average. After last season’s big baseball victory, camp director Winston wants to continue the winning streak. So he’s launched a competitive program for elite athletes—including a new group of girl campers. When Winston enters his charges in a high-stakes basketball tournament, Mack opts out in favor of other, less competitive activities. But Mack starts to suspect he’s being played, as one by one, his favorite camp activities all get closed for repairs. Meanwhile, Winston pits boys against girls in a twisted attempt to win. To undermine Winston’s hypercompetitive scheme once again, Mack creates a plan of his own—but it means he needs to secretly sabotage both the boys’ and girls’ teams. Will Mack match wits with Winston and save the camp from the diabolical director’s clutches once and for all? Or will Mack’s own mischief be exposed—and lose him his summer and his friends? The second Camp Average book is a fast-paced and funny addition to this all-star series.

In the final book of the series, this summer is definitely not average It’s another summer at Camp Avalon―also known as Camp Average to its campers―only this year, things are anything but normal. Mack and Andre are spending the summer at rival Camp Killington, where the competitive campers seem intent on making them suffer. Meanwhile, at Camp Average, Miles is trying to keep the peace―which is not easy, due to obnoxious newcomer Garth and his pranks. On top of that, Miles has another impossible task on his plate: getting Mack and Andre back on home turf. Things come to a head when Mack and Andre are forced apart, and Cassie challenges Garth to a do-or-die ball hockey showdown. Will the Camp Average crew find their way back together and come out on top? In this third and final addition to the series, the campers rally to support each other and discover once more how teamwork and cooperation win.