Laravel MySQL Full text search InnoDB Relevancy Calculation for multiple rows with same number of occurences in total

using mysql from xaamp v8.1.10 along with laravel v5.5.3. Full text Search enabbled in table 'ex1' for column 'des' and 'ft_min_word_len = 1'.

laravel query:

$string='pink item product;

$result = ex::active()->selectRaw("*,match(des) against('$string' in boolean mode) as relevance")->whereRaw("match(des) against('$string' in boolean mode)")->orderBy('relevance', 'desc')->get();

I am getting the result as :

id | Relevance | des

64 | 1.3543391227722 | amazing pink petite lace item is item. 182 | 1.3543391227722 | this pink tall polyester item is item. 598 | 1.3543391227722 | which pink large polyester item is item. 653 | 1.3543391227722 | amazing pink plus size linen item is item. 808 | 1.3543391227722 | what pink tall cashmere item is item. 19 | 1.344024181366 | different pink large silk product is item. 134 | 1.344024181366 | that pink large wool product is item. 140 | 1.344024181366 | this pink tall lace item is product. 233 | 1.344024181366 | new pink extra-small lace item is product. 273 | 1.344024181366 | this pink tall cashmere item is product. 625 | 1.344024181366 | amazing pink medium lace product is item. 893 | 1.344024181366 | that pink extra-small leather item is product. 908 | 1.344024181366 | which pink tall lace product is item. 992 | 1.344024181366 | this pink large cotton product is item. 21 | 1.3337094783783 | that pink extra-small cashmere product is product. 28 | 1.3337094783783 | amazing pink small denim product is product. 71 | 1.3337094783783 | different pink medium cashmere product is product. 225 | 1.3337094783783 | the pink small cotton product is product. 283 | 1.3337094783783 | that pink extra-large silk product is product. 297 | 1.3337094783783 | old pink large lace product is product. 446 | 1.3337094783783 | different pink tall silk product is product. 629 | 1.3337094783783 | this pink extra-small silk product is product. 740 | 1.3337094783783 | new pink extra-small wool product is product. 789 | 1.3337094783783 | what pink extra-small leather product is product.

My question is :

64 | 1.3543391227722 | amazing pink petite lace item is item. and 21 | 1.3337094783783 | that pink extra-small cashmere product is product., though having the same number of occurences:

column 64 has : item-2 times, pink-1 time and column 21 has : product-2 times pink-1 time.

my question is how is the relevance calulated ?

also, even though column 64 and column 182 has same set of occureneces, both has pink-1 time and item-2 times, the relevance for column 64 is higher. why ?

initially i though this was based on row number in database, the order inn which it was created. But inthat case, my first question should be invalid as column 21 should come before column 64. i cant understand how it is calculated.

i did caalculation this far with MySQL doc on full text search and i cant find a documnetation covering this kind of scenario.

Thanks in Advance.

via Chebli Mohamed