“I suppose that’s right”
The word ‘suppose’ adds an air of reluctance to the sentence.
Like the speaker is not entirely convinced or they feel uncomfortable giving an opinion right but if you’re going to twist their arm then they ‘suppose’ that’s right.
If the comment was ‘that’s right’ you could have skipped off happy as Larry with your definitive answer.
But the ‘suppose’ means this conversation might not be over.
Thomas Duggan 