user16912: Is the ultrabullet chess format (15 seconds for all your moves), which has been running on lichess for quite some years now, give chance to give good quality games?
I would like to know on which servers in the past, ultrabullet was played and its origins.

user24693: The origin for Ultrabullet on lichess in particular is an April's fools that somehow stuck around https://lichess.org/blog/WN7V-jAAAAdH8ITR/announcing-instant-chess .
Does it lead to quality games? Depends on what exactly you mean by that. If it is about "objectively good" play in the traditional sense, then the answer is no. Strategically it is played very differently, because of the enormous time pressure. (even just playing moves that allow for a good premove followup as well as playing moves aiming to punish opponent premoves and so forth)
In that sense it may be fair to say that Ultrabullet is more akin to a chess variant with its own dynamics, similar to the likes of Crazyhouse or other variants.

16912: <p>Is the ultrabullet chess format (15 seconds for all your moves), which has been running on lichess for quite some years now, give chance to give good quality games?</p>
<p>I would like to know on which servers in the past, ultrabullet was played and its origins.</p>
 24693: <p>The origin for Ultrabullet on lichess in particular is an April's fools that somehow stuck around <a href="https://lichess.org/blog/WN7V-jAAAAdH8ITR/announcing-instant-chess" rel="noreferrer">https://lichess.org/blog/WN7V-jAAAAdH8ITR/announcing-instant-chess</a> .</p>
<p>Does it lead to quality games? Depends on what exactly you mean by that. If it is about &quot;objectively good&quot; play in the traditional sense, then the answer is no. Strategically it is played very differently, because of the enormous time pressure. (even just playing moves that allow for a good premove followup as well as playing moves aiming to punish opponent premoves and so forth)</p>
<p>In that sense it may be fair to say that Ultrabullet is more akin to a chess variant with its own dynamics, similar to the likes of Crazyhouse or other variants.</p>
