One contributing factor is that after their third match, Agassi picked up a tell regarding Becker's serve and knew where his serves would be directed.
wˈʌn kəntɹˈɪbjuːɾɪŋ fˈæktɚɹ ɪz ðæt ˈæftɚ ðɛɹ θˈɜːd mˈætʃ, ˈæɡæsi pˈɪkt ˌʌp ɐ tˈɛl ɹᵻɡˈɑːɹdɪŋ bˈɛkɚz sˈɜːv ænd nˈuː wˌɛɹ hɪz sˈɜːvz wʊd biː dᵻɹˈɛktᵻd.