Боковое вращение изменило направление мяча.

Literally, боковое вращение means side spin or lateral spin.

• вращение = rotation / spin
• боковое = side / lateral

Вращение is a neuter noun in Russian, so the adjective must agree with it:

• боковой — masculine dictionary form
• боковая — feminine
• боковое — neuter
• боковые — plural

So:

• боковое вращение = side spin

Because the subject, боковое вращение, is neuter singular.

In the past tense, Russian verbs agree with the subject in gender and number:

• masculine: изменил
• feminine: изменила
• neuter: изменило
• plural: изменили

Since вращение is neuter, the correct form is:

• Боковое вращение изменило...

Направление is in the accusative case.

The verb изменить / изменять often takes a direct object, and here the direct object is the direction:

• изменило что? — направление

Because направление is a neuter inanimate noun, its accusative form looks the same as the nominative:

• nominative: направление
• accusative: направление

So even though the form does not change, the function is accusative.

Because мяча is genitive singular.

The phrase направление мяча means the direction of the ball. In Russian, possession or close relationship is often shown with the genitive case:

• направление = direction
• мяч = ball
• мяча = of the ball

So:

• направление мяча = the ball’s direction / the direction of the ball

This is very common in Russian:

• цвет машины = the color of the car
• дверь дома = the door of the house
• скорость мяча = the speed of the ball

It can mean either in English. Both are natural translations.

Russian often uses a noun + genitive structure where English might use either:

• the direction of the ball
• the ball’s direction

So:

• Боковое вращение изменило направление мяча. can be translated as:
• The sidespin changed the direction of the ball.
• The sidespin changed the ball’s direction.

Изменило is perfective.

The infinitive is:

• изменить — perfective
• изменять — imperfective

The perfective is used because the sentence describes a completed result:

• the spin caused a change
• the direction ended up different

So изменило focuses on the fact that the change happened as a whole.

Compare:

• Боковое вращение изменило направление мяча.
  = The spin changed the ball’s direction.
  (completed result)

• Боковое вращение меняло направление мяча.
  = The spin was changing the ball’s direction / used to change it.
  (process, repeated action, or background description)

Grammatically yes, but it changes the meaning.

• изменило = changed in the sense of a completed result
• меняло = was changing / used to change

In this sentence, изменило is the more natural choice if you are describing a specific effect or outcome.

For example:

• Боковое вращение изменило направление мяча.
  The spin changed the direction of the ball.
  (one completed event)

• Боковое вращение часто меняло направление мяча.
  Side spin often changed the direction of the ball.
  (repeated/habitual)

Yes, Russian word order is fairly flexible, though the neutral order here is very natural:

• Боковое вращение изменило направление мяча.

This puts the subject first, then the verb, then the object.

You could rearrange it for emphasis, for example:

• Направление мяча изменило боковое вращение.

This is grammatically possible, but it sounds more marked and emphasizes what changed the direction.

For a learner, the original order is the best default.

Russian has no articles.

So Russian does not directly distinguish:

• a ball
• the ball

That information is usually understood from context.

In this sentence:

• мяча could correspond to of the ball
• in another context, Russian would still use no article

English needs an article, but Russian does not.

You can tell from both meaning and grammar.

1. Meaning:
   It is the thing performing the action of changing.

2. Grammar:
   The verb изменило is in neuter singular, which matches вращение.

So:

• боковое вращение = subject
• изменило = verb
• направление мяча = object phrase

This agreement is a very useful clue in Russian.

Here are the dictionary forms:

• боковое → боковой = side, lateral
• вращение → вращение = rotation, spin
• изменило → изменить = to change
• направление → направление = direction
• мяча → мяч = ball

So the sentence is built from:

• боковой
• вращение
• изменить
• направление
• мяч

A helpful stress-marked version is:

Боково́е враще́ние измени́ло направле́ние мяча́.

Approximate pronunciation:

• боково́е → ba-ka-VO-ye
• враще́ние → vra-SHCHE-ni-ye
• измени́ло → iz-me-NI-la
• направле́ние → na-prav-LYE-ni-ye
• мяча́ → mya-CHA

A couple of notes:

• е often sounds roughly like ye after a consonant in learner-friendly transcription.
• щ in вращение is pronounced like a long soft shch sound.

Yes, absolutely.

Depending on context, good translations include:

• side spin
• sidespin
• lateral spin

If this is about sports, especially tennis, table tennis, baseball, billiards, or similar contexts, sidespin is often the most natural English translation.

So the whole sentence could be:

• Sidespin changed the direction of the ball.

Because Russian often expresses of the ball simply by using the genitive case, without a separate word like of.

English:

• the direction of the ball

Russian:

• направление мяча

There is no word corresponding to of here. The case ending does that job:

• мяч → мяча

This is one of the most important patterns in Russian noun grammar.