Meaning of some sentences from sports pages of newspapers
Solution 1:
Of the four examples you give, you are correct on three of them:
Bears Sack the Pack. (Bears won)
(EDIT) "Sack" is an officially recognized American football statistic in which the quarterback is tackled for a loss of yardage. And "the Pack" is a nickname for the Green Bay Packers who are long-standing rivals of the Chicago Bears.
The Bears won this game, maybe by a little, maybe by a lot; this headline doesn't really say, although if it's not obviously "a lot" then it's probably not remarkable.
Flat Bulls give Rockets a lift. (Rockets won)
"Flat" in this context means "lackluster." The Bulls played poorly, and this is why the Rockets won. Again, nothing says this was a spectacular win, so it probably wasn't remarkable.
Hornets shake, bake Bulls. (Hornets won)
"Shake 'n' bake" is a cooking product that you put in a bag along with meat, then shake it, remove it from the bag, bake it, and eat it. I would guess in this game that the Hornets were behind at first, but "shook" the Bulls by taking the lead, and then "baked" them by thoroughly beating them. The Hornets likely came from behind to win by a large margin.
Hoosiers fake, shake, break Illini. (Hoosiers won)
This game was probably close and quite thrilling. I'd guess here that the Hoosiers were ahead, lost the lead, then regained it by the end of the game. The "break" would indicate breaking Illinois's defense (or morale), so they probably won by a very close margin in the last seconds of the game.
Without knowing which games these apply to, I don't think I could do more than speculate here, but sports headlines do make for some interesting reading. You will very frequently see alliteration, rhyming, puns, and wordplay involving the team names and locations. If you can learn to follow them, I think you might consider yourself a master of English language.
Solution 2:
I had typed this already when Kit's answer appeared, so I'll just post it for the fun of it.
Bears Sack the Pack. (Bears won)
Yes, the Bears probably did win. To "Sack" means (in American Football) to tackle the quarterback before he or she can pass the ball or run it past the scrimmage line. I'd need to know the name of the other team to understand "the Pack" -- I don't really follow football. (As Kit points out, the team is probably the Green Bay Packers.)
Flat Bulls give Rockets a lift. (Flat Bulls won?)
No, they lost, and they aren't the "Flat Bulls," they're just the Bulls. Perhaps they "fell flat," i.e. failed to perform up to their standard. This gave the Rockets a "lift" -- appropriate since they're Rockets -- in the standings.
Hornets shake, bake Bulls. (Hornets won)
Yes, the Hornets won. "Shake 'n Bake" is the trademarked name of an easy-to-prepare food product that has been adopted by sportswriters to describe a performance that made winning seem easy.
Hoosiers fake, shake, break Illini. (Hoosiers won)
Since another answer has just appeared (Kit's), I'll defer to it, adding only that all three of these terms probably suggest particular moves that happened during the game.