Classics, no US entry.
It would be easy to do with worse Brusilov Offensive for Germany initially, but then is stopped anyway. Say pair of old Prussians fuck up and are sacked and sent into a retirement. On 2nd of January 1917, head of OKW is Falkenhayn and General Quartermaster is Mad Hoffmann. Falkenhayn opposed USW as he believed that there is no need to poke Us with needle.
USW vote on Crown Council fails thanking to Chancellor Betmann Hollweig and 2 aforementioned persons.
From here, Entente has 2 cases.
Best : October Revolution doesnt happen, or fails, PG stays in power Italy collapses after Caporetto, while Kerensky quits in January of 1918. War ends in January 1918 , with Entente having to cede Belgium, and Russia ceding
@Kaiserboi version of Brest Litovsk territory. Bulgaria gets Macedonia and Dobruja, and Entente gets Ottoman Empire remnants as consolation prize.
Worst: UK starts to almost literally cannibalize it's own Empire to keep allies afloat. Italy BARELY holds after Caporetto, Russia goes as OTL, and come Spring-Summer 1918, remaining Western Entente members are swept by tidal wave of German offensives.
It all ends then somewhere in 1918, with Germany taking Belgium, probably adding to puppet belgium state Lille and Pas-De-Calais departments, taking from Belgium lands to Meuse, and annexing Nancy depratment from France outright. On the East full 100% Brest Litovsk Treaty would come to life.
Bulgaria gets everything they wanted, and Entente gets Ottoman Empire remnants as consolation prize