Okay, last night I was retrying to radar-chain Sneasel because I've spent a whole 4 days without getting a single shiny of that devious weasel. It's always the Snovers and Gravelers breaking my chain.
After a few failures last night because of Snovers, I retried about the seventh time and the chain peaked at 7. On the 8th re-scan after a few radar resets, There wasn't any sparkly grass yet so I walked to the grass farthest to me - It's a little around the edge of the grass area - since Smogon stated that the farthest grass to you is the one that has the highest chance of continuing the chain. The grass I walked to was not sparkling. The encounter showed up....
And it was a Shiny Sneasel. Is this guy full-odds or is he boosted by Radar-chains?