LogFAQs > #964527460

2008: overachieved, won title
2009: underachieved, dominant regular season but kg got hurt and the team lost in round 2
2010: overachieved, made finals
2011: met expectations, lost to lebron and wade
2012: overachieved, won two playoff rounds and took lebron and wade 7, with a lead in game 7
2013: met expectations, lost in round 1 with really old players +ray allen desertion + rondo tearing his ACL
2014: met expectations in a tanking season
2015: exceeded expectations, made surprising run to make ir to the playoffs after reading for IT and crowder midseason
2016: met expectations, made playoffs and lost in round 1
2017: exceeded expectations, got the #1 seed and made it to the ECF before getting smashed by the best cavs team of all time
2018: exceeded expectations, survived hayward and irving injuried to win the #2 seed and get 7 games into the ECF
2019: drastic underachievement, only 48 wins with the same core as 2018 plus kyrie and hayward - losing to giannis that year was nothing to be ashamed of, but obviously round 2 and the manner of loss was embarrassing
2020: exceeded expectations, survived kyrie and horford leaving and hayward getting injured again (lol) to win two playoff rounds in the bubble before flaming out vs miami (not a great kid admittedly, but definitely still an overachieving season)
2021: underachieved, weak 7 seed in an injury-plagued season with an injured brown in round 1. that said, we were the only team to face KD, harden, and irving at full strength - this healthy core should 100% have won a title

so i don't think we've really underachieved as an aggregate in that time