The escape of most of the Dutch fleet was more significant than its losses, as only its destruction as a fighting force would have given England the early victory it needed. That possibility became more remote as senior Dutch sea officers and politicians began to consider the reasons for the disaster at Lowestoft, and identified three principal causes. The first was the lack of discipline that was dealt with by severely punishing the worst offenders while rewarding success. The second was tactical, as the favoured Dutch tactic of the undisciplined mêlée, with individual ships boarding and capturing their opponent and, in many cases, leaving the battle with their prize, was ineffective against English gunnery on ships fighting in line. Although de Ruyter did partially revert to mêlée tactics in the last day of the Four Days Battle., fighting in line became the standard tactic in new Fighting Instructions approved by the States General in August 1665. The final cause was the inferiority of Dutch ships which, though well-constructed, were generally smaller and more lightly armed than those of other maritime nations. Although there had been a significant building programme after the First Anglo-Dutch War, only "Eendracht" and "Groot Hollandia", built as fleet flagship, were comparable to English ships of the third-rate. Although from 1660 the Dutch embarked on an expansion programme, many where smaller ships and only one exceeded the size of the "Eendracht", equaling an English second-rate. This building programme was greatly expanded after the outbreak of the war, but none of its ships had been completed by the time of Lowestoft. Compared with the Dutch fleet at the Four Days' Battle in June 1666, Obdam had a fleet comprising many older and smaller vessels and fewer modern ones. It relied strongly on the East Indies Company's ships and other merchantmen, although these did not have the resilience of true warships. There were no East Indies Company ships in the battles of 1666, and the few merchant ships present were not in the line of battle but acted as auxiliaries.