Ugh! I just typed a long detailed reply and must have timed out so I lost it all. I'll be briefer now.
The best defense against long losing streaks is simply a high individual game win rate. These are the chances of losing 5 straight games at win rates between 50-70%:
<TABLE style="WIDTH: 96pt; BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=0 width=128 border=0 x:str><COLGROUP><COL style="WIDTH: 48pt" span=2 width=64><TBODY><TR style="HEIGHT: 20.25pt" height=27><TD style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 48pt; BORDER-BOTTOM: #ece9d8; HEIGHT: 20.25pt; BACKGROUND-COLOR: transparent" align=right width=64 height=27 x:num>50</TD><TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 48pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right width=64 x:num="3.125E-2" x:fmla="=0.5*0.5*0.5*0.5*0.5">3.13%</TD></TR><TR style="HEIGHT: 20.25pt" height=27><TD style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-BOTTOM: #ece9d8; HEIGHT: 20.25pt; BACKGROUND-COLOR: transparent" align=right height=27 x:num>55</TD><TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right x:num="1.8452812500000006E-2" x:fmla="=0.45*0.45*0.45*0.45*0.45">1.85%</TD></TR><TR style="HEIGHT: 20.25pt" height=27><TD style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-BOTTOM: #ece9d8; HEIGHT: 20.25pt; BACKGROUND-COLOR: transparent" align=right height=27 x:num>60</TD><TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right x:num="1.0240000000000004E-2" x:fmla="=0.4*0.4*0.4*0.4*0.4">1.02%</TD></TR><TR style="HEIGHT: 20.25pt" height=27><TD style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-BOTTOM: #ece9d8; HEIGHT: 20.25pt; BACKGROUND-COLOR: transparent" align=right height=27 x:num>65</TD><TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right x:num="5.2521874999999982E-3" x:fmla="=0.35*0.35*0.35*0.35*0.35">0.53%</TD></TR><TR style="HEIGHT: 20.25pt" height=27><TD style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-BOTTOM: #ece9d8; HEIGHT: 20.25pt; BACKGROUND-COLOR: transparent" align=right height=27 x:num>70</TD><TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right x:num="2.4299999999999999E-3" x:fmla="=0.3*0.3*0.3*0.3*0.3">0.24%</TD></TR></TBODY></TABLE>
The more often you win, obviously the less susceptible you are to a long losing streak. As far as chases, there's really no reason to play them because if your win rate is strong enough to win by flat-betting then why risk your entire bankroll by chasing losses? If you can't beat flat-betting, then your win rate is too low and therefore too risky for a chase based on the above numbers. For example, if your individual games hit 50%, you would lose a 3-game chase 12.5% of the time, or 1 in 8. So, if each series loss loses you 8 units it's not helping you is it?
Martingale is the riskiest (worst) progression out there. The key to testing any progression is your return on investment. Calculate your total wagers and divide by your profit/loss, then compare that to flat-betting the same games. You'll figure out that you're not helping yourself. That's assuming the standard progressions that have been around forever like Martingale, Labourchere, D'Alembert, etc. I've tested progressions most of my betting life and found a style that seems to outperform flat-betting, at least so far, but you have to add variables to it. For example, Labourchere has several variables such as deciding how to set up your betting line, i.e. length and amounts. I personally do not like the Labourchere though.