diagonal: <Congratulations to Bologan>
Yes, of course, but it has to be added, that the annual Poikovsky tournament cultivates a rather similar and homogenous group of same participants again and again, there is quite a stable stock of frequently invited players, eg. Shirov, Onischuk, Motylev, Moro or Bolo. Especially Viktor Bologan got <an invitation almost always, he played 15-times within 16 years> (as of 2015):
He was invited from 2000 to 2010 eleven times in a row, and since 2012, (only "missing" the tournament in 2011).
Can’t recall such a series in any other international invitation tournament of note; oops: Van Wely got a spot at Wijk aan Zee - A group already more than 20-times (never reaching the podium until now; well, he will surely be invited again next year...)
Back to Siberia: This year’s international tournament in Poikovsky saw nine out of ten invited players coming from the former Soviet Union (the handwriting of A. Karpov), the only player not fitting this criteria was Viktor Laznicka.
In the field, no youngster under 25 years, no veteran as let’s say Beliavsky (Big Al never ever was invited), rather biased, all players born between 1968 and 1988.
It's a fact, that the Poikovsky tournament, started in 2000, with the invited player being more or less of same strength (meaning no top ten grandmasters, as well as no fodder players), rarely invited a player of Karpov's own generation (eg. Beliavsky, or in earlier years Ljubojevic, Hübner, not to mention Portisch or Korchnoi).
Anyway, I just want to pint out, that <multiple wins at a closed invitation tournament have to be related to the number of invitations>, especially if a player is (arbitrarily) invited by the organizers in 15 out of 16 editions.
It's math & stats: compare eg. Shirov, another repeatedly invited participant at Poikovsky, in 2006 he won outright (that year Bologan was sole last / ten players of near even strength), in 2009 then Shirov was sole last with two points / ten players, sometimes (including the recent two years), Shirov placed in-between. Statistically perfectly sound, the normal distribution predicts some stochastic expectation for the outcome in the long run on average (Gauss could have formulated it better, though).
Bologan has an ELO of 2607 (October), now 2630 (November), Beliavsky, a fighting player too, still rated 2622 ELO (October and November), but within sixteen editions, he never was invited, in such cases, it's even deterministic: you have no chance to win! Am I little bit too sarcastic? *sorry*
Congratulations to GM Viktor Bologan, Moldava - and honourable reminiscence: Biggest tournament success of Bologan: Dortmund 2003 (winning outright ahead of joint runners-up Anand and Kramnik, 6 players): Dortmund/Sparkassen Chess Meeting (2003)