Igors Rausis is a (now) Czech grandmaster, age 58, whose rating was generally in the low 2500s or high 2400s. A fine player in his own right, of course - making GM is always impressive, even if we tend to take them for granted when we focus on the players fighting for the world championship. Still, while a GM, he was no world-beater. But then, suddenly, in his 50s, his rating started to climb...and climb...and climb. By means of brilliant training, and/or cleverly selecting his tournaments and opponents, and/or...another method, he made it all the way up to 2686.
Alas, it appears that "another method" is at least part of the story. Looking at the screen shot of his recent opponents from the 2700chess site, it looks like part of his strategy was to take on as many tomato cans (relatively speaking) as he could. But the big story is that he cheated using a cell phone in the bathroom, a point which isn't merely an allegation as he has admitted it (and there's a photo as well). The only question is whether it was a one-off or if it played a significant role in rise into the upper 2600s. Will the evidence strongly confirm the hypothesis that he cheated in other games? We'll see. He says he's retiring now - not that he's likely to have much of a choice about this - but one can hope that this will dissuade others from thinking they can get away with cheating using their smartphones. I don't know what will happen once people start having chips inside their bodies, but hopefully the smartphone menace can be tamed, for now.