How strong is Roshi?

[LowRyder2005]

Could be anywhere from Nappa to Gyniu force tier. I'd say he's most likely at least Nappa tier.

Freeza's goons, the ones armed with guns and pretty much cannon fodder, felt really comfortable tackling Nameks around 1.000 BP (all the while saying they were weaklings), so we could as well infer that the average Freeza's soldier may have been around 2.000 BP or so during the Namek Saga.
Of course, they're not the same guys, but I don't think Freeza's would have recreated an army that much weaker than before. If anything, we'd be inclined to believe they are stronger as they give Super Namek Piccolo (leagues above 1.000.000), Krillin and Tien a run for their money.

Moreover, Roshi literally fights a hundred or so of those soldiers by himself, if he was < 1000 chances are he would've found a soldier above that power level, dropping out before Goku's arrival.

[Marco Polo]

Of course, they're not the same guys, but I don't think Freeza's would have recreated an army that much weaker than before. If anything, we'd be inclined to believe they are stronger as they give Super Namek Piccolo (leagues above 1.000.000), Krillin and Tenshinhan a run for their money.

But Freeza was dead for decades. I'm pretty sure he explicitly note that his army is in a sad state after his resurrection. It can easily be weaker soldiers on average.

[LowRyder2005]

Of course, they're not the same guys, but I don't think Freeza's would have recreated an army that much weaker than before. If anything, we'd be inclined to believe they are stronger as they give Super Namek Piccolo (leagues above 1.000.000), Krillin and Tenshinhan a run for their money.

But Freeza was dead for decades. I'm pretty sure he explicitly note that his army is in a sad state after his resurrection. It can easily be weaker soldiers on average.

Possibly, yes. Nevertheless, it would still feel very strange that warriors <1000 or <500 could make everyone consider the possibility of losing if they're not careful enough.
In the end, as strange as it sounds, Roshi's performance is still comfortably comparable to that of the others.

Unless you want to strongly believe that Roshi got lucky and fought only people <200 while everyone else got people strong enough to give them trouble... but, well, I think that percentage-wise is unlikely.

[Blackstripe]

Yeah, Roshi was taking out quite a lot. I really doubt that all the ones going for him just happened to be the "weak" ones.

Amusingly, though, despite undergoing a massive power up, the old man still neglected to learn how to fly.

[Lord Beerus]

I'd personally see Roshi at atleast Vegeta (Saiyan arc) tier by the time of ROF

[irreality]

I'd personally see Roshi at atleast Vegeta (Saiyan arc) tier by the time of ROF

That seems like a lot, given Vegeta at the time was among the strongest fighters in Freeza's army. I would say he is more likely like Yajirobe or Radditz power at the time -- strong enough to take on most mooks in Freeza's army, but not strong enough to take on his stronger fighters, and plausible that he doesn't fly since Yajirobe doesn't. Maybe in that order of magnitude at most. Like in the 1k-3k range.

[Lord Beerus]

I'd personally see Roshi at atleast Vegeta (Saiyan arc) tier by the time of ROF

That seems like a lot, given Vegeta at the time was among the strongest fighters in Freeza's army. I would say he is more likely like Yajirobe or Radditz power at the time -- strong enough to take on most mooks in Freeza's army, but not strong enough to take on his stronger fighters, and plausible that he doesn't fly since Yajirobe doesn't. Maybe in that order of magnitude at most. Like in the 1k-3k range.

Honestly though, I'd see the majority of Freeza's Army to have an average BP of 3,000, and given that Roshi was kicking their assess effortlessly like he was in the movie, he'd have to be at least 10 time stronger than them. I mean, he was knocking most of Freeza's soldiers out with one casual punch. The gap has to be quite huge between him and Freeza's soldiers for him to pull that off.

[Doctor.]

3 thousand is too much. Raditz wouldn't even ask for Goku's help if Freeza's army was that strong. Also Vegeta with 24k on Namek easily defeated Cui, so a 25% difference is basically enough. If Roshi is twice as strong as the soldiers, then it's enough. I put Roshi at 1k, with the average soldier around 300, which was Goku's level in the beginning of Z.

[Blackstripe]

I put him at about Nappa's level myself.

...If he's not stronger than Yamcha. Which I kind of like as a concept, since it shits on Yamcha some more.

[LowRyder2005]

I think the real problem most people are underestimating is that Roshi - being supposedly one of the weakest characters by Z and beyond - is really hyped during the fight. We may argue that, except for really minor stuff, his perfomance is perfectly comparable to that of everyone else.
The only one who seems to do considerably better than the rest of the gang is Gohan (he saves Krillin and acts pretty confident throughout the whole ordeal). Everyone else, from Piccolo to Roshi, is gasping for air or having troubles keeping their ground at some point.

Keeping the speculation at bare minimum, as contradicting as it sounds, the fight actually suggests that at the very least Jaco, Tien, Krillin and Roshi are in the same ballpark figure or that Roshi, while weaker, is not that far off when fighting seriously by the time Revival of F takes place.

That's why the weaker you make the soldiers appear to be, the more far-fetched it sounds. I mean, you can come up with reasons like "during the chaos all the weak ones went after Roshi while the strong took everyone else","fighting dozens of fodder opponents will make it so there is no difference between power levels", it's an almost impossible fight to judge without taking it for badly written, create contradictions with everything Dragon Ball established so far or just thinking it's a mass of plot-induced stupidity... because at least Roshi and Krillin think the army (Frieza not included) may kill them if they're not careful, and no one of the others disagree.
Conversely, making them really strong and taking the idea Roshi trained in-secret to become at least decently strong by Z-standards fits... well, better, unfortunately.
Another reason to really doubt the "weak soldiers" theory is that the soldiers take Kamehameha and Kikohos right in the face during the whole fight and Freeza, who watched the whole thing, at the end says that the Z-Fighters "didn't kill any of his soldiers out of kindness" (although he could have been referring just to the ones laying on the ground).

Rewording my previous statement, for what we know Roshi took Frieza's training routine, became almost as strong as Super Namek Piccolo... and, taking a purely objective perfomance evaluation of all fighters it would still make more sense than "all Freeza soldiers have three-digit power levels". Silly? I know, but if anything it shows the big faults in Revival of F's script.

In the end, I still believe that good ol' Roshi's power is just about Nappa (I personally think he put just a dozen of soldiers to sleep, didn't even move from where he started and fired just a couple of Kamehamehas, while everyone else ran around and used ki intensively), but it's still subjective.
His real combat prowess is extremely complex to gauge at this point, with just the material we have.

[irreality]

Piccolo also fought against Shisami, though, which I'm not sure the rest of them would have. But Gohan is shown to be much better than Shisami.