Each year, a handful of new additions — some hyped, some under the radar — become the catalyst for playoff runs across the NFL. In 2018, players like Trey Burton, Michael Crabtree, and Denico Autry each turned non-threatening teams into contenders. The year before, new signees like A.J. Bouye, Calais Campbell, Robert Woods, and Andrew Whitworth all sparked major turnarounds.

So who will be the players who change addresses in 2019 and help make also-rans into contenders? There are more than 700 free agents available to teams this offseason, most of whom can’t be signed until March 13 — the official start of NFL free agency. This year’s defense-heavy crop features pocket-ripping pass rushers, ball-hawking defensive backs, rangy linebackers, and one All-Pro running back who hasn’t played in more than a year.

They’ll compete for a share of more than $1.1 billion in salary cap space this spring as stars throughout the league fulfill their dreams of securing the bags and turning their underpaid rookie contracts into mega-deals.

Unfortunately for the franchises behind them, free agency isn’t always a panacea. The players who earned the five richest contracts of 2018 all wound up on non-playoff squads. Sammy Watkins got $30 million guaranteed to haul in 40 receptions for the Chiefs. Case Keenum was so uninspiring as the Broncos’ quarterback he was replaced by someone worse than he was.

While there’s a real hit-or-miss element to this year’s group of available players, there’s no doubt at least a handful will go on to play meaningful roles on a deep march into January, and possibly even Super Bowl 54.

So, who makes up 2019’s top free agents? Check back often as we’ll update the list as guys get signed.