Definitive list
2003 Roddick
2004 Federer
2005 Federer
2006 Federer
2007 Federer
2008 Djokovic
2009 Nadal
2010 Federer
2011 Djokovic
2012 Djokovic
2013 Nadal
2014 Djokovic
2015 Djokovic
2016 Djokovic
2017 Federer
2018 Djokovic
2019 Djokovic
2020 Djokovic
2021 Djokovic
2022 Alcaraz
2023 Djokovic
Djokovic on top in 11 years. And 10 in last 13 times. Only Elbow Injury, 2013 Rafa and Covid stopped him from featuring in this list.
Federer in this list for 6 years. The gap is 13 years between 2004 to 2017, which is lesser than the gap between Djokovic 2008 to 2023 which is 15 years.
Despite Nadal being KOC, he appears on the list 2 times. In 2009 and 2013. Injuries stop him from getting into the upper tier in 2010. Or a chance to be in another best on HC year.
Murray appears 0 times on the list. He achieves more than Roddick in 2003 but has competition of 16950 Djokovic in 2016.
Alcaraz does not have the accolades yet but he is just the right man at the right time here.
Delpo, Cilic, Wawrinka, Thiem and Medvedev who are the only 5 players who won slams outside above guys are never in the race to be called the best on HC.
Overall HC GOAT Djokovic, previous HC GOAT Federer and Nadal is sandwitched between these two. Otherwise he could be best in 2008 on HC, 2010, 2011 as well to add to his 2009 and 2013. Not too bad for the KOC. He is better on HC than any of the non big 3 bozos in past 20 years.