Final week of the NFL's regular season arrives with No. 1 seeds still undecided in AFC and NFC

The NFL's regular season has reached its final weekend with plenty undecided in terms of the playoff picture, including the No. 1 seed in both the AFC and NFC.

Here's what to watch over the next few days:

AFC playoff picture

The Denver Broncos, New England Patriots and Jacksonville Jaguars all have a shot at the No. 1 seed in the AFC, which includes a first-round bye and home-field advantage through the playoffs.

The Broncos (13-3) have the clearest path — if they beat the Los Angeles Chargers (11-5) on Sunday, they'll earn the top seed. They could also sneak into the top spot depending on the results for the Patriots and Jaguars.

The easiest way for the Patriots (13-3) to earn the top spot is to beat the Miami Dolphins (7-9) on Sunday and hope the Broncos lose to the Chargers. There are also a few unlikely scenarios — including ties in Week 18 — where they could clinch.

The only way the Jaguars (12-4) will be the No. 1 seed is if they beat the Tennessee Titans (3-13) on Sunday and the Broncos and Patriots both lose. Jacksonville can also clinch the AFC South with a win.

The Baltimore Ravens (8-8) and Pittsburgh Steelers (9-7) are fighting for the AFC North title and the final AFC playoff spot on Sunday. The Steelers need to win or tie while the Ravens have to win.

NFC playoff picture

The Seattle Seahawks (13-3) face the San Francisco 49ers (12-4) on Saturday night with the NFC's No. 1 seed, first-round bye and home-field advantage on the line. The Seahawks have to win or tie while the 49ers must win.

The Carolina Panthers (8-8) face the Tampa Bay Buccaneers (7-9) on Saturday for the NFC South title and final NFC playoff spot. Carolina's easiest path is to beat or tie the Bucs, but the Panthers could also sneak into the playoff field if they lose and the Atlanta Falcons (7-9) beat the New Orleans Saints (6-11).

Tampa Bay must beat Carolina and then hope the Falcons lose or tie.