Your definition of serious and my definition of serious might be quite quite different. I'm talking about having models that track how the public bets certain games historically, having money on 15 different books so I can line shop, knowing what line shopping actually is, knowing how to have long term profitability off wong teasers, knowing the exact % off the top of my head in a split second to be successful on my bets at every single vig rate from -105 up to -280, tracking my bets meticulously, and doing analysis on my betting every six months to look for leaks and weaknesses, knowing who Mr. Wong is and why he is so important, know who the big syndicates are and where they are putting their money, know why betting non conference basketball games with teams not ranked in the top 25 is profitable because of market inefficiency.
So yes, as someone who devotes that much time and energy to sports betting - I know all the people who are as serious as I am.