University at Buffalo star Khalil Mack became the first top-10 draft choice to reach a contract agreement this year, signing with the Oakland Raiders, the team announced.

Mack, the 6-foot-3, 251-pound linebacker, was drafted fifth overall. His deal, first reported by ESPN, is worth a total of $18.67 million over four years, according to multiple reports. He gets a signing bonus of $11.9 million.

The parameters for rookie deals are tightly structured under the terms of the league’s collective bargaining agreement, which makes their negotiation much easier to complete.

Mack was ranked as roughly a third-round draft pick after his junior year at UB. That would have garnered him a contract worth about $2.8 million. So by staying in school and having a great senior season, Mack probably made himself about $15 million. The rookie deal he signed is fully guaranteed.

The deal with the Raiders is very close to the one signed by last year’s No. 5 overall pick, Detroit’s Ziggy Ansah, who got $18.59 million. Last year’s No. 4 overall pick, Lane Johnson, signed for $19.8 million, with a $12.8 million signing bonus. Buffalo drafted receiver Sammy Watkins No. 4 overall this year. Watkins can expect a deal very similar to that of Johnson.