Some years ago, when I first began sportsbetting, I believed watching line movement was a very good indicator of who would win the game.
I remember betting a 3 team college football parlay where there was very significant line movement toward the favorite in all 3 of my picks.
In that 3 teamer, I lost to the number by an aggregate 97 points.
(This is no BS)
I didn't say "those teams sucked", but I did say "I have no idea what the hell I'm doing."
So I decided to forego the idea of making a profit in betting on sports, and instead, tried to learn every thing I could about handicapping.
I scoured the web. Read everything I could get my hands on. Asked stupid questions.
Took a couple of years, but I learned a lot.
This is one of the things I learned regarding line movement...
(These are my words)
"If a line moves more than 2 points in one direction, the House will USUALLY (not always) beat the bettor more often than not."
Line movement is tricky. It takes a very experienced, seasoned handicapper to understand the meaning of early moves or late moves as the line approaches game time.
Hope this helped.
Good luck.