I would quite surprised if they managed to sell 100-200-300% more than they can produce. Outselling the PS4 2:1 would entail 500k regular weeks and likely 2-3 million holiday weeks. That's more than the DS could do back when it shipped about 30 million or more for one fiscal year.

The problem with including Nintendo into the standard generational classifications is that PlayStation & Xbox are now running longer generations than the historical average. It used to be that systems peaked by their second full year (maybe later in unusual circumstances), and were replaced in 5-6 years tops. But last generation was longer, perhaps deliberately, with the PS3 & 360 lasting 7 and 8 years respectively before being replaced and not peaking until 2011, far later than any systems that preceded them. The Wii meanwhile lasted only 6 years before the Wii U came out, and the Wii U has already been replaced despite coming out only 4-½ years ago. Nintendo's systems still follow historically "normal" sales curves. The Wii peaked in 2008, and the Wii U peaked in 2014. In all likelihood, the Switch will peak no later than 2019. Meanwhile, the PS4 and XBO are only just now cresting their peaks, and depending on how fast they decline, probably won't be replaced until 2020, plus or minus a year. This means that the Switch will have passed its own peak and entered the terminal decline phase of its life when the PS5 and Xbox 4 are in their infancy, and the Switch's successor will likely come out no later than Nov. 2022. This is an extremely likely scenario based on historical trends.

It also leads one to ask, "If the Switch is Gen 9, then will its successor be Gen 10 even though it came out only two years after the PS5 did?" And looking even further out, we are faced with the prospect of Nintendo kickstarting Gen 11 right when Sony & MS are only just entering Gen 10. A decade from now, the whole idea of continuing to shoehorn Nintendo into the traditional numbered generations thing will look absurd if we insist that each subsequent console from them heralds the start of a new numbered generation. If we must assign consoles into a numbered generation, it ought to be defined in terms of competition. The Switch will be spending its prime years being nominal competition for the PS4 and XBO, not for the PS5 & X4. The idea of two consoles from one brand in a single generation is not unprecedented; in the conventional numbering scheme widely used today, which lumps all pre-crash-of-'83 cartridge-based systems into the "Second Generation," Atari did just that, releasing the 2600 and 5200 in the same generation. It is worth pointing out that http://strategy.sauder.ubc.ca/nakamura/iar515p/gallagher_innovation.pdf">older sources split Gen 2 into two separate generations, though, with the 5200 & Colecovision being considered a different generation than the systems released in the late 70s; interestingly, Coleco referred to the ColecoVision as a "third wave" system, and several media sources from back in 1982 referred to both the ColecoVision and 5200 in the same way. But the Wikipedia convention, which has since become the standard on internet discussions (even though their fusion of all pre-crash cartridge-based systems into a single gen is largely original research), lumps the 2600 and 5200 into the same generation. That pre-crash generation was a bit of a clusterfuck, but it is what it is.

In any case, Nintendo is effectively desynchronized from PlayStation & Xbox. That means we should either start to exclude them from the standard numbered generations, or classify their systems based on what their primary competition is during the main part of their life cycle.

The Master System is simply the Western name for the Sega Mark III, which is simply an enhanced version of the SG-1000. The SMS was basically the Pro/Scorpio of its generation, though only Japan got the older versions of the hardware. The SG-1000/SMS platform started in 1983 in Japan, same as the NES.

The Dreamcast was considerably more powerful than the N64. Its GPU was upwards of 14 times as powerful, it had 6.5 times as much RAM as a base N64, and its CPU was over twice as fast. It was far closer to the PS2 than to the N64 in terms of power. And it launched only 15 months before the PS2 did in Japan. The N64 was a little late to the game in Japan (which used to get any given console much earlier than the West did), but the Dreamcast's power and release timing puts it square in the same generation as the PS2.

And again, if we use the "Switch is the Wii U's successor, and Wii U was Gen 8, so Switch is Gen 9" logic, it will start to get absurd fast. This right here is a very possible timeline we could be looking at:

No matter what anyone pushes here Switch is a Gen 9 platform simple as that as it's a successor to gen 8 platforms much in the same way the person who is elected after Trump will be the 46th President.

So if Nintendo decided to release the successor to the Switch in 2021, Gen 10 would start? A "generation" refers to multiple systems over multiple companies so the, "It's a new console +1 gen" logic doesn't work if companies follow different release schedules. You'll get to a point where Nintendo release there "Gen 11" machine before Sony/MS have even released a "Gen 10" machine. 

The US Presidency is singular, a console generation is a group, bad analogy.

There's nothing to stop a company releasing there next-gen console every 3 years, next release = +1 is a completley flawed defintion for an industry-wide generation.

The Switch is Nintendo's next generation console, that's it.

A President or Prime Minister in the UKs case can be replace before the usual term is up so the analogy is fine it's happened here in Britain twice in the last decade it doesn't stop the replacement being classed as the next President or Prime Minister it's happened in South Korea this year. Show me where it is written in law that a company has to follow a schedule to be defined as a gen, the is none only what people have made up in their heads a gen is not an industry wide thing it never was it was an individual classification for platform released by companies.

What blows your argument out the water is the SMS and Megadrive which released 3 years from their predecessors and where all different gens, companies didn't follow schedules they released platforms strategically which forced other companies to react and people mistook that as some gentlement agreement that the is this schedule that needs to be stuck to.

So PS5 can be classified as a 10th generation machine? But no the analogy is not fine, a generation contains multiple systems, the 8th president is always referring to one individual, there can never be more then one president at a time. Meanwhile the 8th generation refers to multiple different entities all belonging to the same group.

I have no idea how you think, a president (individual), is a good analogy for Generation (group).

New Console = +1 is not a valid defintion for a shared generation, and like it or not 6th,7th,8th,9th generation, these are shared, not individual classifications, these refer to a group of systems. Generations are archaic and going the way of the dodo, but anyone insisting on using them must have a defintion for generation better than "it's another system though!"

What if Nintendo released a successor in 2019, would that be the start of 10th gen? You can't take one companies release schedule as a definitive line for a generation, as the generation covers the whole industry thus it needs to take the whole industry into account.

A console generation is a group of consoles, thus for it to be part of a generation it needs to be grouped with other devices, and a reason for being grouped with those devices as opposed to others.

So PS5 can be classified as a 10th generation machine? But no the analogy is not fine, a generation contains multiple systems, the 8th president is always referring to one individual, there can never be more then one president at a time. Meanwhile the 8th generation refers to multiple different entities all belonging to the same group.

I have no idea how you think, a president (individual), is a good analogy for Generation (group).

New Console = +1 is not a valid defintion for a shared generation, and like it or not 6th,7th,8th,9th generation, these are shared, not individual classifications, these refer to a group of systems. Generations are archaic and going the way of the dodo, but anyone insisting on using them must have a defintion for generation better than "it's another system though!"

What if Nintendo released a successor in 2019, would that be the start of 10th gen? You can't take one companies release schedule as a definitive line for a generation, as the generation covers the whole industry thus it needs to take the whole industry into account.

A console generation is a group of consoles, thus for it to be part of a generation it needs to be grouped with other devices, and a reason for being grouped with those devices as opposed to others.