I love Kenenisa Bekele like he's my best friend, and I root for him above ALL other runners, and I think he's the BEST of all time...but, as much as it pains me to say it, he's simply the BEST, not the GREATEST. The title of The Greatest should probably remain with Haile Gebrselassie.
Even if Kenenisa achieves the same pb's as Haile in the half-marathon and marathon (or wr's like Haile, for that matter), Haile still did something that Kenenisa will almost certainly never be able to do: MEDAL IN 6 CONSECUTIVE WORLD CHAMPIONSHIPS. Bekele medaled in 4 straight, competed in 5 straight, but broke the streak in 2013 for sure. Bekele would have to become a finger of God and compete into his 40's now in order to re-create Geb's streak (although I wouldn't put it past Bekele, lol).
Haile also competed in 4 straight Olympics, finishing no worse than 6th in all 4. Bekele NEEDS to compete in Rio 2016 and finish 6th or better in some event to be on the same level.
So there's some stuff that Bekele needs to do to 'equal' Haile.
Now, onto Farah. In addition to everything that Weldon, Robert, Steve, and John of LR said....
I'd like to point out that even if Farah wins gold in 2015, he'd have to medal in 3 MORE world championships ON THE TRACK to be in the same ballpark as Geb on the track. Does anyone else really think that's going to happen? Hell, Farah has to win gold through 2017 just to equal Bekele's streak of consecutive golds.
FARAH IS A PAN-FLASH. He looks like a 'goat' now, but 2011 through a tiny part of 2015 is nothing compared to the time that Kenenisa or Haile spent at the top. FARAH WOULD HAVE TO DOUBLE THE DURATION OF HIS ERA OF DOMINANCE TO EVEN EQUAL THAT OF BEKELE.
Farah's not even as good as Bekele. Bekele ran the Golden League circuit (pre-dated the Diamond League) and won it twice. Keep in mind that not every distance had a Golden League prize every year, and the 5,000m was in the "not" category. Furthermore, the 10,000m wasn't even part of the Golden League jackpot. So Bekele, had he the chance, may have won it many times more than twice. But the point is, BEKELE WASN'T SITTING ON HIS ASS, HIDING IN TRAINING, OR PUTTING IN 2 OR 3 RACES A YEAR BEFORE THE WORLD CHAMPIONSHIPS; BEKELE WAS RACING HIS HEART OUT --AND-- WINNING WORLD GOLDS. Farah is simply NOT racing as much. Farah needs too much time to recover in order to race as much as Kenenisa did, so FARAH'S GOLDS AT WORLDS DON'T MEAN AS MUCH AS BEKELE'S GOLDS.
Yet another reason Farah's Golds don't mean as much as Bekele's: Bekele had to run sub-26:50 for 2 of them. Farah didn't have to do anything near that. IT'S NOT JUST A PROBLEM THAT FARAH DOESN'T HAVE FAST TIMES, IT'S THAT HE NEVER HAD TO RUN A FAST TIME TO WIN.
In general, a sit-and-kick gold doesn't mean as much as a fast gold. As a ridiculous hypothetical to illustrate this, let's say the 5,000 were run at 7-minute pace for the first 4600m, and Michael Johnson in his prime were in that same race with Farah in his prime. When it comes down to the last lap, who's going to win the race? Of course Johnson would blow away Farah in the final 400m, but that doesn't make Johnson a great 5,000m runner.
For that matter, who's to say that Kenenisa in his prime, if challenged properly, wouldn't have unleashed an even greater kick than he did for many of his races? Let's select Bekele's 2004 Olympic race as an example. The next best guy, Sileshi Sihine, was more than 4 seconds behind. 4 seconds!!! Bekele ran 53.02 for the last lap in that race WITHOUT being pushed AT ALL by the competition, faster than Farah's 53.48 while winning the Olympic 10,000m in 2012. It's also very significant that, in the SLOW Olympic 5,000m race that followed, Farah ran his balls off holding off 5 guys for gold, and ran 52.94 in the last lap...barely better than Kenenisa did with no competition in a race twice the distance.
Farah is NOT the 'goat.' He is NOT in the discussion for 'goat.' GOAT CANDIDACY AT THIS POINT IS FOR KENENISA, HAILE, AND OTHERS, not Mo.
I'll close with memories of the 2008 Olympic 5,000m final. Let's begin with the fact that Kenenisa ran sub-13 to win it. 12:57.82 to be precise, and he didn't need a freaking pace-setter to do it. He DOMINATED the last 5 laps by front-running, turning in a 4:56.97 final 2000m, and going un-challenged (again) in the final lap (the next fastest guy, Eliud Kipchoge, was 4.98 seconds behind). In the final 1600m Kenenisa turned in very nearly a 4-minute mile, running one of those laps in 59.9 seconds, and doing it all like he's ordering a pizza (easily; just watch a video of it sometime and look for the smile on his face while he was doing it, let alone the ease of his body-action). Now, you tell me, does anyone out there really think that a guy (Kenenisa Bekele) doing all that at the end of an OLYMPIC 5,000m is inferior overall to Farah at that distance when both are in their prime?