The teams that go on surprise runs in the playoffs are often the teams that are peaking at the right time. While some teams will peak halfway through the season and find themselves on the decline by the time the playoffs start, the teams that peak at the right time are truly dangerous.
Just ask the 2020 version of the Pittsburgh Steelers, who went 11-0 before finishing the season by losing five of their last six. They were one-and-done in the playoffs. Conversely, the 2005 Steelers rode a four-game winning streak into the playoffs and continued that all the way to a Super Bowl championship.