Why do they say "strike" and "spare" in bowling?

Bowling has German roots, strikecomes from the German, streik, which means a blow or a hit. As for spare, it refer to the spare pins left over after the first ball. The ones that were spared.

Why is basket worth two point?

In some very early leagues ,around 1902, a field goal was one point and a foul shot a halh point. People don't like fractions because they're unwieldy. Then a field goal is two point and a foul shot is one point.

Why differentiate field goals from free throw?
It was a rougher game, with tackling and grabbing. Getting a basket was alot harder. A free throw is easier. It shouldn't be worth as much.

Why are the score love/15/30/40 in tennis?

It comes from an old French coin, the 60 sou. Tennis was played for stakes. The sou could be broken into four pieces, so each point was worth one quarter of coins, or 15. And 40 was a shortened version of 45. A zero written down is kind of oval shaped. The French would say "l'oeuf",which means egg. The English thought they were saying "love".
p.s.: Deuce, a deux in French, means two to win.

Why is a perfect game 300 point?

Thomas Curtis who is widely regarded as the father of tenpin bowling came up with the 300 point scoring system around 1895.

Why do baseball games have nine innings?

The American thinks that nine is the number of supreme intelligence. So, 90 feet between bases, nine men per side, nine innings.

Why are there 18 holes in a round of golf?

The early golf courses had no fixed number of holes. Some were 5, some 7, some 12. At the Royal and Ancient Golf Club of st. Andrews, we had 11 holes that went straight along the water. they'd play 11 out, turn around, and play the same 11 back. A round was 22 holes.
At Oct. 4, 1764, the first four holes were too easy, so they made them into two. That made 9 holes out , 9 back , 18 holes.