Nine of BYU's opponents ended up in a bowl game, however only four those teams went on to win in their bowl games.
Every year there are always some teams that appear to be better or worse than they actually are once the season actually ends. It isn't hard to see this with teams like Stanford who started the season ranked in the Top 25 but ultimately ended up with a 4-8 record. This can also be seen with BYU opponent Tennessee. At the time it didn't feel like a great win, but after the Vols ended their season on a six game win streak, suddenly that win may be the best of the season for BYU.
Let's take a look at all of BYU's opponents to see how they ended their seasons and then evaluate the season as a whole. For the sake of space, Idaho State and Hawaii will be left off this list.
Utah
Let's be honest, who would have been motivated to go from the NCAA Playoff to playing in the Alamo Bowl against Texas? Well, that motivation cost them as they were blown out by the Longhorns. Despite this, their 11-3 record will go down as one of their best seasons ever.
Overachieved
Tennessee
As mentioned above, Tennessee started off the season really bad starting off the season 1-4. Something happened after that though as the Vols finished 7-1 with their only loss coming in a closer than expected loss to Alabama. This team ended up being BYU's best win of the season.
Overachieved
USC
Who was USC? They beat Utah and Arizona State but lost to BYU, Washington, Notre Dame and Oregon. In their bowl game they got blown out by a better than expected Iowa team. Overall USC was the team that never really lost to teams they should beat (other than BYU) but never beat the teams ranked above them.
Met Expectations
Washington
Washington may have been the biggest disappointment on BYU's schedule. The Huskies had really great moments including blowing out BYU and Boise State but they had some really questionable losses to California, Stanford and Colorado. The Huskies finished with a 8-5 overall record, but their convincing 38-7 win against Boise State in the bowl game will give them momentum going into the off season.
Underachieved
Toledo
There was only one team in the FBS that was bowl eligible that did not end up playing in a bowl game. The only reason why Toledo was bowl eligible though was because they took down the Cougars. Toledo finished with a meh.. kind of season with some really high scoring games and some really disappointing losses including five of their last seven games. How BYU lost this game is a mystery.
Underachieved
South Florida
This was rock bottom for BYU. The USF Bulls were 4-8 and lost five of their last six games. In fact, in the final five losses they only scored 44 points, only 17 more points than what they scored against the Cougars. Aside from UMass or East Carolina in 2016, this may be the most embarrassing loss looking back at it since BYU went Independent.
Met Expectations
Boise State
Aside from losing to BYU, Boise State had a really good regular season despite battling injuries about as much as BYU did. The Broncos actually played in five one score games during the regular season and went 4-1 in those games. BSU could have easily had three of four losses this season, but the Broncos found ways to win games. That was not the case in the Bowl Game beating smacked 38-7 by the Washington Huskies.
Met Expectations
Utah State
The hype around this team in the preseason was really high in large part to Jordan Love and his NFL Draft stock. Without a strong defense or great receivers though, Love was unable to produce a season that would be special for the Aggies. The Aggies were just lucky to reach a bowl game after a 7-5 season. It would have likely been better for them not to make a bowl game however as they fell 51-41 to Kent State, a team from the MAC that had to win their final four games just to make it to the postseason.
Underachieved
Liberty
It is tough to get a good read on Liberty. They weren't really expected to do much this season and were seen as an automatic win around Cougar Nation. The Flames gave BYU a run for their money but ultimately fell short 31-24. The rest of the season the Flames beat G5 bottom feeders and lost to P5 teams by quite a bit. Liberty did finish with a nice bowl win against Georgia Southern. Overall, this team did get more wins than anyone thought they did, but they did it in an ugly way.
Overachieved (Barely)
UMASS
When you are 40+ point underdog to a 2-9 Northwestern team you already know that this is going to be an underachieving team. As bad as this team was expected to be, nobody saw them giving up 40 points or more in all but one game. The only team they beat (barely) was an Akron team that ended up going 0-12.
Underachieved
San Diego State
San Diego State may be the most overachieving team on BYU's schedule. Nobody saw them starting 7-1 overall and finishing with a 10-3 overall record. If SDSU had any pulse on offense, they would have easily made it to the MWC Championship game and finished ranked this season. In their three losses, Utah State was the highest scoring opponent with only 23 points.
Overachieved
Overall, four teams ended up overachieving from preseason and early season expectations, four teams underachieved and three teams finished about where they were expected to finish.
Weird how that works itself out isn't it?