and how they stack up within that stratified variable. QBR may not be the most relevant statistic to judge true freshman QB's. It obviously takes time and experience to adjust to the speed of the game at the next level. So they are obviously not going to be as efficient. Where I think the most telling variable comes from is looking at productivity and the final result on the field.

Using this criteria, let's look at a few of them....

Heaps went 5-1 his last six games, and almost beat #20 Utah at RES. He broke Ty Detmer's Freshman TD Record, a record that stood for 22 years with 15 touchdowns. Per Wikipedia:

In the month of November and the December bowl game, Heaps threw 13 touchdowns and two interceptions and passed for 1,259 yards. He was the first freshman quarterback to ever lead the Cougars in Brigham Young's 29 bowl game appearances. Heaps was named the New Mexico Bowl's Most Valuable Player,[6] breaking some of the bowl's records after leading BYU to a comfortable victory with a quarterback rating of 122.5 throwing 4 touchdowns with 1 interception. As a true freshman, Heaps threw for 2,316 yards, 15 touchdowns, and 9 interceptions with a quarterback rating of 116.2. He completed 219 passes on 383 attempts with a completion percentage of 57.2% He was named first team Freshman MWC QB.

It was clear that he was improving and that he was able to produce for the cougars - heck, even breaking TFD's 22 year TD pass record.

Taysom only played in 6 games before the injury, but in those 6 games he was clearly talented and I don't think anyone was uncertain about his future at the QB spot. Again, it's hard to make too much of a judgment based on only 6 games of action. For instance, Jake Heaps really turned it on he last month as a starter, based on the improvement Taysom made from his freshman to sophomore years, I think its safe to say that he would have most definitely improved as the season progressed.

Tanner did pretty well his freshman year... per wikipedia:

In his first career start he passed for 309 yards with two touchdowns and two interceptions and helped lead BYU to victory by completing a 35-yard touchdown pass on fourth-and-seven with 45 seconds left in the game to give BYU the lead.[13][14][15] He finished the season with 3,377 passing yards along with 23 passing touchdowns and 10 interceptions, breaking numerous BYU Freshman passing records, including a career-high 365-yard passing game against UConn. For his performance during the season he was named Freshman of the Year by the Touchdown Club of Columbus.

Zach Wilson, per Wikipedia:

As a true freshman at BYU in 2018, Wilson played in nine games and made seven starts. He started his first career game against Hawaii, becoming the youngest quarterback to start a game for BYU.[3] He finished the season having completed 120 of 182 passes for 1,578 yards with 12 touchdowns and three interceptions.[4] He was named the MVP of the 2018 Famous Idaho Potato Bowl after completing all 18 of his passes for 317 yards and four touchdowns.[5]

Again, not bad. Certainly exceeded expectations for a true freshman QB.

What's interesting is that Jaren and Baylor both had the lowest statistics and accomplishments than any of the freshman QB's on this list, yet it seems like they are potentially some of the better freshman QB's we have had - as you stated yourself.

Conover has nothing to really be evaluated on, except for the feedback we've received based on his practice squad numbers....it's been said that our defense owed a lot of their success due to having to face Conover each week in practice as he was "better than almost every QB they faced during the games through the actual season. To me, that says a lot.

So, yeah, I don't think they have been overrated at all - just my opinion though, perhaps you have other reasons beyond QBR?