I don't want to come across as a "know it all", although, the way I say things makes one depict that thought on how I am, but to answer your question, I don't have any one direct reason why the lines move the way they do, although the so called "computer boys" when they pounce on a play, they have followers and the word gets around to other heavy hitter players who in turn join along on a play as they did on the Phillies last night but in turn they pounded the Dodgers run line, again that is going on once again, but also a few nights ago, the computer boys "Billy Walters" network, pounced on the Reds vs the Nats in the short series, they did it again last night on 7 1/2 over on the NYY/Oak game for today.
Other line moves come from lineup announcements in which some bookmakers will make 5 and 10 cent line changes due to a player being out or coming back, like today with the Royals losing Alex Gordon for 6-8 weeks, while the Royals lost a run producing bat, they replaced him with a speed demon and have some depth on their bench, also sharps jumped on the anti-Ventura band wagon since he got ding donged around his previous 4 starts and was making his first start in some time.
So in short, moves are made by the money placed on side/total/run lines and news of players/pitcher being out, scratched, once team trainers make announcements and/or lineup cards are made up.
Some books also change the total line once the weather report is out, like in Wrigley for instance a few weeks back, the line was at 10 1/2 for a day game with the wind blowing out and a total of 3 runs were scored. :facepalm:. There have been more unders played at Wrigley this season than in seasons past, but that will change soon once the weather sticks to a summer weather pattern in Chi-town, if it does and the wind does consistently blow out, the lines for totals will adjust for their games at home.
GL Bosco and thanks for asking! Glad you hit on KC!
GL tonight everyone!
Major Line move by computer network, "UNDER" 7 Pitt/STL, now at 6 1/2 will drop to 6 perhaps, I know with my new local he has it at 6 1/2 -125.