Why does church tradition teach that one third of the angels fell with Lucifer when no verse supports that The verse used is Rev. 12:4, but the context takes place in the midst of the great tribulation and not before Adam sinned.  Daniel 8:10 seems to confirm that the  stars that the dragon flung down were good angels, as he trampled them.  Those are the only 2 verses in the Bible dealing with this question that I can find and both infer that the 'stars' were enemies of the dragon not his fellow angels.
Is there something that I am missing here?
@BYE points in the right direction. Some of the prophecies in Revelation look backwards to events that occurred before John lived, because the contest between Satan and God goes back to the beginning of the world.


  12 A great sign appeared in heaven: a woman clothed with the sun, with
  the moon under her feet and a crown of twelve stars on her head. 2 She
  was pregnant and cried out in pain as she was about to give birth. 3
  Then another sign appeared in heaven: an enormous red dragon with
  seven heads and ten horns and seven crowns on its heads. 4 Its tail
  swept a third of the stars out of the sky and flung them to the earth. (Revelation 12:1-4)


Verse four is interpreted by some to represent angels as stars. Thus the stars that fall to the earth are fallen angels, and they number one third of all stars, hence one third of all angels.


  Jamieson-Fausset-Brown Bible Commentary
  
  
  drew—Greek, present tense, "draweth," "drags down." His dragging down the stars with his tail (lashed back and forward in his fury)
  implies his persuading to apostatize, like himself, and to become
  earthy, those angels and also once eminent human teachers who had
  formerly been heavenly (compare Re 12:1; 1:20; Isa 14:12).
  


This commentary considers several possible meanings, including the stars being angels or martyred Christians.


  Expositor's Greek Testament 
  
  Revelation 12:4. The symbolism is a
  reminiscence of an ætiological myth in astrology (cf. the cauda of the
  constellation Scorpio) and of the primitive view which regarded the
  dark cloud as a snake enfolding the luminaries of heaven in its
  hostile coils (Job 3:8; Job 26:13, with A. B. Davidson’s notes). Thus
  the Iranians (S. B. E. iv. p. lxxiii., Darmesteter) described the
  fiend as a serpent or dragon not on the score of craftiness but
  “because the storm fiend envelops the goddess of light with the coils
  of the cloud as with a snake’s fold”. The same play of imagination
  would interpret eclipses and falling stars, and, when the pious were
  compared to stars (as in Egyptian theology, Plut. de Iside, 21), it
  was but a step to the idea of Daniel 8. (cf. Sib. Or. ver. 512 f., the
  battle of the stars), where Antiochus Epiphanes does violence to some
  devout Israelites who are characterised as stars flung rudely down to
  earth (i.e., martyred, 1 Maccabees 1.) Originally, this description of
  the dragon lashing his tail angrily and sweeping down a third of the
  stars probably referred to the seduction of angels from their heavenly
  rank (so 8–9) to serve his will (Weiss). But John, in recasting the
  tradition, may have thought of the Danielic application, i.e., of the
  devil succeeding in crushing by martyrdom a certain number of God’s
  people. In this event, they would include at least, if they are not to
  be identified with, the pre-Christian martyrs of Judaism (cf. Hebrews
  11:32 f. Matthew 23:35).—ἕστηκεν, a conventional posture of the
  ancient dragon cf. e.g., Pliny, H. N. viii. 3, “nec flexu multiplici
  ut reliquae serpentes corpus impellit, sed celsus et erectus in medio
  incedens”; ibid. viii. 14, for serpents devouring children. The mother
  of Zoroaster had also a vision of wild beasts waiting to devour her
  child at its birth. This international myth of the divine child
  menaced at birth readily lent itself to moralisation, or afforded
  terms for historical applications, e.g., the abortive attack on Moses,
  the prototype of messiah (Baldensperger, 141, 142) at his birth (Acts
  7:20 f.) and the vain efforts of Herod against the messiah. The
  animosity of Pytho for Leto was due to a prophecy that the latter’s
  son would vanquish him.


This commentary also agrees that the stars are angels:


  Pulpit Commentary
  
  Verse 4. - And his tail drew the third part of the stars of heaven, and did cast them to the earth; draweth (Revised
  Version). Not the stars with which the woman is crowned (see ver. 1),
  but other stars. In describing the vast power of the devil, St. John
  seems to allude to the tremendous result of his rebellious conduct in
  heaven, in effecting the fall of other angels with himself (Jude 1:6).