What a week for John Chayka and the Maple Leafs.A Joseph Woll trade on Tuesday, the hiring of Jim Hiller as head coach on Wednesday, and a seismic sign-and-trade for Darren Raddysh in the early morning hours on Friday.An eight-year contract for Raddysh, with an $8.5 million cap hit, is the biggest swing of them all. Raddysh was destined to be the best (or second-best) defenceman available in free agency this summer, but he’s also 30 and coming off his one and only one spectacular season in the NHL — a 22-goal, 70-point extravaganza for the Tampa Bay Lightning in the wake of injuries to long-time No. 1 defenceman Victor Hedman.All of which makes this a bold and risky bet for the Leafs and their new GM.Flyers trade Samuel Ersson, Emil AndraeKevin Kurz and Madison EadesIt’s not as outlandish as it might seem, though.Take the contract to begin with.An $8.5 million cap hit is large certainly, especially for someone with such a limited track record, but we also need to adjust the way we look at it to account for the salary cap rising to $104 million next season and $113.5 the season after that.Next season, for instance, it’ll be the equivalent of a $7.2 million cap hit two seasons ago when the cap was only $88 million.Morgan Rielly’s eight-year extension with the Leafs in the fall of 2021 came with a $7.5 million cap hit that ate up just over 9 percent of the cap.Raddysh’s deal is a little less than that, just over 8 percent next season — and less and less from there. If last season was real, or even real-ish, the Leafs will be getting value from the contract, at least in the short term.It’s a long deal, obviously, as long as it gets, and for a defenceman who just turned 30 in February. The risk isn’t just that last season was a mirage of some kind, but that Raddysh falls off a cliff sooner than later and the Leafs are stuck with a giant anchor on their books until 2034, potentially, when the deal expires.Raddysh is only two years younger than Rielly, who showed signs of decline in his age 30- and 31-year-old seasons. The Leafs also have Chris Tanev, who will be 37 in December; Jake McCabe, who will be 33 in October; and (maybe) Oliver Ekman-Larsson, who turns 35 in July.Things may change still, but this remains an older defence with Raddysh in the mix.But here’s the other thing — maybe the most important thing in all this: The Leafs need to keep Auston Matthews, the most important figure in the organization, happy.The team’s captain has only two years remaining on his contract. But it’s really more of a year-by-year thing at this point.Which means the Leafs, at minimum, just need Raddysh to pop next season. If he does, and the Leafs bounce back and make the playoffs, the chances increase that Matthews will sign an extension next summer or, at the very least, commit to sticking around for the final year of his contract.And if things go wrong next season, because of Raddysh and/or for other reasons, it’s all over anyhow.The Leafs will have to trade Matthews, and likely William Nylander, and start again. At which point, the size of Raddysh’s deal matters much less.