Rabby250

(Also what I wonder is whether the chances of encountering a shiny had been increased. Instacheck uses that shiny values that are 12-bit long while the determination stays the same (XOR first 12 bits of LPID, UPID, SID and TID etc). If still the 13-bit numbers were used for determining shininess like in previous generations, there would have been a load of false positives within Instacheck and people would notice it early since very many people use it, but somehow I am not sure if I am just missing something that makes the chances remain 1:8192 instead of 1:4096.)

The original Shininess Determination prior to Gen VI was XOR result (16-bit) < 8 (= 2 ^ 3), therefore you have to match 16 - 3 = 13 bits.

In XY however, there are reports of Shiny Pkxs whose XOR result falls between 8 and 15. This leads to the speculation of the threshold being raised to 16 (= 2 ^ 4), which will yield a 16 - 4 = 12 bit match.

The chances are thus 2 ^ -13 = 1/8192 and 2 ^ -12 = 1/4096 .

By the way, can we confirm the threshold by intentionally set up a breeding of non-Shiny with XOR result 16?

Fairly sure anything in the range 0 to 7 gives shiny, not just 0. That makes it the 8 in 65536 chance that has remained the same since the first shiny Pokemon in GSC.

The right shift (>>) already excluded the 0 to n range, so what Kaphotics said was correct.

(The only change was that in previous generations, the shift value was 3.)

It might be that 0x18-0x1B is actually the PID and the value at 0x0 is just an unrelated number.

Found an article (in Japanese) by rusted_coil describing that spot patterns of Spinda can be fixed along with IV inheritance by the breeding mechanism similar to BW2 (1), but the shiny status can't (2). Perhaps this implies that either Spinda spots or shiny check was no longer dependent on PID?

Edit: both (1) and (2) are quoted in the article; (1) can be found by following the "さきさんの記事" link, and (2) can be found in the Twitter links.