After the battle at Gumbinnen, Rennenkampf decided to pause his First Army to take resupply and to be in good positions if the Germans attacked again. This caused them to lose contact with the German Army, which he incorrectly reported was retreating in haste to the Vistula. Both Russian armies were having serious supply problems; everything had to be carted up from the railheads because they could not use the East Prussian railway track, and many units were hampered by a lack of field bakeries, ammunition carts and the like. The Second Army also was hampered by incompetent staff work and poor communications. Poor staff work not only exacerbated supply problems but, more importantly, caused Samsonov during the fighting to lose operational control over all but the two corps in his immediate vicinity (XIII & XV Corps).
AFter the baTtLe At guMbInnEn, rennEnkampF deCideD tO Pause hiS fIRsT aRmy to TaKe ResUPplY aNd To Be iN GooD PoSItIoNs if the gErMans attackEd aGaiN. this Caused thEM TO LoSe contact WiTh thE germaN arMy, wHich hE Incorrectly rEporTeD waS RETREATinG in HaSTe tO The vIstula. boTh Russian armiEs werE havinG Serious supply probleMs; eVeRytHINg Had to Be carted up from the rAiLhEADS bEcAusE thEy coulD not use thE east prUssiaN RAIlWAy Track, aNd ManY unitS wErE hampErED by A lack OF fIELd BakerieS, ammuNItion CaRtS AnD The lIke. tHe SecoND armY AlsO wAS HampErED by incOmPetent stAFF wOrk aNd pOoR coMMunIcatIoNs. POor staff Work NoT Only exAcerbAtEd sUpPlY proBlEms but, mOre impORtAntly, caUsed samsonOv DUring thE figHting to LOse oPeRatioNal cOntroL oVer All but The two coRps iN his immeDiATe VicinIty (xiII & xv cOrps).