Napoleon was too quick for Blücher: he decimated Lieutenant General Olssufiev's Russian IX Corps at the Battle of Champaubert (10 February). There were 4,000 Russian casualties and Russian General Zakhar Dmitrievich Olsufiev taken prisoner, to approximately 200 French casualties. This placed the French army between Blücher's vanguard and his main body. Napoleon turned his attention to the vanguard and defeated Osten-Sacken and Yorck at Montmirail on 11 February; There were 4,000 Coalition casualties, to 2,000 French casualties. Napoleon attacked and defeated them again the next day at the Battle of Château-Thierry. There were 1,250 Prussian, 1,500 Russian casualties and nine cannons lost, to approximately 600 French casualties. Napoleon then turned on the main body of the Army of Silesia and on 14 February defeated Blücher in the Battle of Vauchamps near Étoges, pursuing the latter towards Vertus. There were 7,000 Prussian casualties and 16 cannons lost, to approximately 600 French casualties. These disasters compelled the retreat of the whole Silesian army, and Napoleon, leaving detachments with Marshals Mortier and Marmont to deal with them, hurried back to Troyes. Analysis Ralph Ashby wrote in Napoleon Against Great Odds (2010): David Zabecki wrote in Germany at War (2014): Michael Leggiere in Blücher: Scourge of Napoleon (2014) quotes Johann von Nostitz that the campaign displayed Napoleon's "talents as a field commander to the highest degree in defeating five enemy corps in sequence", but in failing to totally destroy Blücher's army and driving the remnants back into Germany, Napoleon missed his only opportunity of forcing the Coalition Powers to agree to anything other than peace on their terms. Aftermath Napoleon inflicted further defeats on both Schwarzenberg's and Blücher's armies. Thus after six weeks fighting the Coalition armies had hardly gained any ground. The Coalition generals still hoped to bring Napoleon to battle against their combined forces. However, after the Battle of Arcis-sur-Aube on 20 March, where the Austrians outnumbered his dwindling army 80,000 to 28,000, Napoleon realised that he could no longer continue with his current strategy of defeating the Coalition armies in detail and decided to change his tactics. He had two options: he could fall back on Paris and hope that the Coalition members would come to terms, as capturing Paris with a French army under his command would be difficult and time-consuming; or he could copy the Russians and leave Paris to his enemies (as they had left Moscow to him