In many other N.F.L. off-seasons, a swap of quarterbacks once drafted No. 1 over all, with a bundle of early-round future picks also involved, would signify the boldest, most intriguing move of the winter. But the trade consummated on Saturday by the Detroit Lions, who agreed to take on Jared Goff’s onerous contract from the Los Angeles Rams to sweeten their return for Matthew Stafford, might just be a prelude to a series of wild quarterback deals and signings over the next two months that upend the N.F.L. landscape.
About half of the league’s 32 teams ended the regular season with uncertainty at the quarterback position.