An introduction to my timeline is the assumption that the Grand Duke of Lithuania, Jagiello, however, would take part in the Battle of Kulikovo, on the side of the Golden Horde. The battle would end then surely defeat the Grand Duke of Moscow, Dmitri, and the expansion of Lithuania permanently headed by confidently east. Let's start in order:
September 8, 1380 in the late afternoon, Jagiello and Mamai sit down to a feast of victory on the fields under Kulikov, bearing at his table for the guest of honor at the tastefully studded spear head the Bonn Dimitri. While their centurions drink beer / wine / kumys, they sober share Rus, which, bled, is not able to issue any vital army. Orda takes a Ryazan, Upper Oka Principalities, Tver and Moscow and Jagiello - Pskov and Novgorod.
* 24 XII 1380, Novgorod, Jagiello - realizing that as a Gentile is unlikely to restrain their power over eastern orthodox part of the principality, solemnly adopts Novgorod Orthodox baptism with all his court, becoming from that moment Vladimir Olgierdovitch. He assumes the title of King of the whole Russia. Consciously and deliberately set in opposition to the Kestutis and Vytautas, the ongoing paganism.
* 1380 to 1383, civil war in Lithuania. Standing at the head of the Orthodox Ruthenian Vladimir Olgierdovitch rebukes regiments Kestutis and Vytautas. Kestutis soon after the defeat dies, Vytautas flees to Malbork under the protective wings of Konrad von Zollner Rotenstein. Casus belli for the Order. At the same time ...
From 1381 to 1384, the war of Mamaia Khan of the White Horde, Tokhtamysh, supported by Tamerlane. At the end of Tokhtamysh wins.
* 1384, May, Vladimir, beaten but not defeated by the Teutonic Knights in Kaunas, waives Samogitia and adopt a co ruler Vytautas.
* 1384, July, palace coup, Vytautas goes to the dungeon for seven years. Another casus belli for the Order.
* 1384, September, again winning the Order, Vladimir waives on his behalf all the lands west of the upper Narew - Niemen - Neris - Swieta. Compensates for these losses offensive in the east. Using the still ongoing turmoil in the Horde sweeps Upper Oka Principalities, Rzhev, coming around Tver, Moscow and the White Lake.
* 1385-1400, the state of temporary equilibrium, all three countries (the Teutonic Knights, Lithuania - or rather the Kingdom of Rus' and Orda) need peace to digest absorbed prey and consolidate the acquired positions. The Teutonic Knights are still one of the two main enemies of Rus Lithuania, the second - in place of Moscow - becomes Orda.
That front is more important, where to look for victory?