Brannen won his first New Brunswick Tankard in 2016 as lead for Mike Kennedy with teammates Scott Jones and Marc LeCocq where they went a perfect 8–0.

The team finished 3–4 at the 2018 Papa John's Pizza Tankard, failing to qualify for the playoffs.

[6] After starting 1–2, they upset higher seeds Ontario's John Epping and British Columbia's Steve Laycock to sit in a good spot going into their final two games.

As the reigning provincial champions, Team Grattan was invited to represent New Brunswick at the 2021 Tim Hortons Brier, which they accepted.

[8] One member of Team Grattan, Paul Dobson, opted not to attend the event due to travel restrictions.

[10] At the Brier, the Grattan rink had a strong start, defeating higher seeds Mike McEwen and Brad Jacobs to sit at 4–1 with three games left.