Updated Sep 29, 2015 at 4:10p ET

Each Tuesday, WhatIfSports.com’s NFL simulation engine generates predictions and box scores for every NFL game for the coming week. Our highly sophisticated algorithms simulate every play of every game to produce each team’s likelihood to win. Each matchup is simulated 501 times.

To account for injuries and roster moves announced late in the week, we will be re-simulating games on Thursdays through the season.

Note: our predictions use the latest available team and player information, while NFL SimMatchup includes all players that were or will be available at any point during the 2015 season so that theoretical and “what if” scenarios can be simulated.

Week 3 in Review

Offenses around the league kicked it into high gear in Week 3, putting up huge totals across the board. Our NFL simulation engine bounced back and went 13-3 this week, correctly predicting the Packers as the Game of the Week winner and the Seahawks as the lock of the week. The engine also put up a winning record (7-6) against the spread.

Nailed It: Our NFL simulation engine predicted that the Panthers would beat the Saints by an average score of 25-23. The real final score? Panthers 27 – Saints 22. That’s about as close as it gets.

Wide Right: The upset pick from Week 3 was the Chargers defeating the Vikings. The NFL simulation engine had the Chargers winning 58.5 percent of the time by an average score of 25-22. Instead, the Vikings blew out the Bolts, 31-14.

Track our 2015 performance or view our accuracy last season.

Week 4 Game to Watch

Houston at Atlanta: The Falcons have shocked the league by starting off 3-0, but they’ll face a tough test with Houston’s tough defense and ground-and-pound attack coming into town. The simulation engine has this being one of the closest games of the week, with Atlanta narrowly squeaking out a win 54.5 percent of the time by an average score of 24-21.

Week 4 Upset Pick

Pittsburgh (+2.5) over Baltimore: Our NFL simulation engine has Week 4 playing out by the books, as there’s only one upset choice predicted. Without Ben Roethlisberger, the Steelers are underdogs (+2.5) at home against the Ravens in a must-win game for Baltimore. Our predictions have the Steelers pulling it out 52.5 percent of the time by an average score of 24-23.

Fantasy Radar

Fantasy Start – T.Y. Hilton, IND: Our prediction engine has T.Y. Hilton listed as the top-scoring receiver on the board in Week 4, putting up 12.1 points against a very vulnerable Jaguars secondary.

Fantasy Sit – Alfred Morris, WAS: After a stinker last week against the Giants, our engine doesn’t have the former fantasy star doing all the well against the Eagles, either. In fact, it’s RB Matt Jones who is projected to be the fantasy points leader in Washington’s backfield this week.

Fantasy Add – Karlos Williams, BUF: If he was left on the wire in your league, go get him. With LeSean McCoy projected to sit out, the engine has Williams finishing as the 6^th highest scoring RB in Week 4 with 15.1 points.

For more fantasy football tips, view our Week 4 player projections.

For additional content, view our Week 4 NFL power rankings, NFL archive or sortable weekly NFL predictions.