His track record shows that he makes sound draft picks in the first round. No silly reaches or out of left field head-scratchers.
2013 - 1.11 T Fluker - drafted for need; never played up to draft position; not terrible but disappointing overall
2014 - 1.25 CB Verrett - terrible pick; he was a known major injury risk entering the draft and played just 25 games in 5 seasons for the Chargers; complete bust
2015 - 1.15 RB Gordon - terrible decision to trade up to draft Gordon; never played up to his draft position and had extremely negative holdout in his 5th year option season; poor draft pick and terrible trade
2016 - 1.3 Edge Bosa - good pick, but hard to go wrong between Bosa, CB Ramsey, and IDL Buckner, who was my preference; has never played up to his potential, largely due to inability to stay on the field, but that isn't on Telesco
2017 - 1.7 WR Williams - did not like the pick at all at the time, and don't think he truly delivered full value for his draft position, but he did finally break out in his 5th season, just in time for a big contract extension
2018 - 1.17 S James - seemed like a great pick at the time but has been hit or miss, playing well in 3 seasons, missing most/all of 2 others due to injury, and unexpectedly dropping off a cliff in 2023
2019 - 1.28 IDL Tillery - terrible pick; ultimately released midseason in his 4th year and was a bust up to that point
2020 - 1.6 QB Herbert - great pick, obviously
2020 - 1.23 LB Murray - terrible pick and even worse decision to trade up to draft him
2021 - 1.13 LT Slater - great pick
2022 - 1.17 G Johnson - jury's out; starter for first 2 years, which is good, but play has been disappointing, especially in year 2
2023 - 1.21 WR Johnston - jury's out, but his rookie season was a disappointing bust, to put it mildly
I count 4 good/great picks in there (Herbert, Slater, James, Bosa), 3 mediocre picks (Williams, Fluker, Johnson), and 5 bad picks (Verrett, Gordon, Tillery, Murray, Johnston (so far)). I have no idea how that compares to the Raiders track record over the same period.