When I moved to Las Vegas in the late 90's, I became friends with someone in my new circle who was from Brooklyn, NY and a pretty active sports better. I mean this wasn't the recreational type doing for-fun $20 parlays on Sunday, he was routinely doing $500 and $1k bets ("dimes" he called them). I had been to Vegas on trips before and remember bringing $300 for gambling for a weekend and thinking that was a lot. I was in utter shock at how much he would be riding on a typical NCAA Football Saturday and NFL Sunday. It was one of my first true experiences in my life of what hardcore gambling was and a side I have never seen or known.

Anyway, I remember very clearly how serious his betting was and how he solely looked to find any edges he could. It wasn't about handicapping a game, he was a line sharp. Remember this was a time where Internet was still dial-up and wagering off-shore was still very early days. Many times he would be calling old-fashioned bookmakers back home. He was paying for a service called Don Best and at the time it was pretty expensive but was able to get line-moves almost in real time. He was "Chasing Steam" as you called it. Watch for big line moves in Best and place bets where he could that haven't caught it yet. He was pretty successful and quit his full time job while buying a house, cars, etc. Not flashy but just a living.

Eventually, as all things gambling, it started to turn bad for him. He was getting accounts suspended and getting listed as a sharp. He would call customer support playing dumb and I remember one guy at an offshore book on speaker-phone flat out told him basically no longer want his business as every time he places a bet with them the lines were moving shortly after in his favor and wanted to know what he was using.

I remember his downfall being pretty fast after that. It started with just getting blacklisted at some and the few reputable offshore books left wouldn't keep him long when they discovered he was a steam chaser. He tried changing phone numbers and fake ID's and they caught onto that. Eventually any book that did take his action he started to hear Don Best line moves in the background on the phone and they would tell him to "hold on something is happening" then just give him the new adjusted line. The edge was gone and he started to bet with shadier old-school bookies that didn't have the technology, but they just didn't pay him anyway.

He started to see the writing on the wall and the bill pressures started to effect him as he started to just push into trying to handicap and pick winners based on gut and dabble into some line making software. At one point he was in for a very large sum after a bad Sunday, something like $70k he owed. He struggled for a good 5 years after that, divorced and back to a 9-5. Last I seen him was right before Covid and he was out of that world not having placed a bet in a long while he said and was now into options trading.

I doubt betting line moves is even a thing anymore. Information just moves so fast now and books have evolved way beyond. Plus with how big sports wagering in in the US, lines probably only move now because of large public betting waves or injuries.